"It's not contingency work and there isn't really a risk of non-payment with a client like Apple." This isn't quite true, non-payment is often a bill-reducing tactic.
:)

I'll answer your last question, and one someone else posted. I simply don't have time at the moment to get into a protracted discussion right now, humorously due to dealing with lawsuits, so this will have to be my last real response. I actually don't have a dog in this fight, even though i'm a corporate IP lawyer. I actually also manage a team of software engineers, and spend most of my time on the legal front either dealing with open source licensing, or trying to put myself out of business by getting rid of software patents.

On the corporate side:

Money from these cases doesn't go to hiring more lawyers. Ignoring NPEs and other weird cases, in most companies, the number of lawyers is fixed relative to the size of other things, like any support staff.
For example, i can name a huge tech company where lawyer headcount is limited to 1% of engineer headcount.

Until engineer headcount increases, winning or losing lawsuits has no impact on the number of lawyers being hired or paid. It does not make the lawyers more or less money.

Again, the above is common even in companies that derive large amounts of money from licensing (though i'm still excluding NPE's).
They are simply "understaffed" and deal with it.

Please also note that corporate lawyers nowadays often make less than equivalent engineers, unless you are talking about the very top folks. People do corporate law because of better hours, not better money.

On the law firm side:

There are too many lawyers already. The vast majority of lawyers coming out of law school right now cannot find jobs.
Vast majority being 70+%.
It's no longer economically worth being a lawyer, in the sense that the debt you incur is more than your expected increase in earnings.

For the first time in a long time, law schools and the ABA are actually starting to tell students it's not worth it, too.

A large number of firms are downsizing heavily, including IP firms.

This in turn, has caused two things to happen:

1. Good lawyers are looking for work, and willing to work cheap. very cheap.

2. Cheap fresh-out graduated law students are willing to work for basically nothing, because they have debt but no jobs. "Basically nothing" = there are large numbers of fresh-outs from top schools willing to work for 20 bucks an hour. No joke.

This, combined with outsourcing (which most find a hilarious thought), is seriously pushing down the hourly/etc price of lawyers. The amount of profit you will now make in a trademark suit, even with a client like apple, is not that large, but the expenses haven't changed, because law firm structures haven't changed. You would think #2 would just cause law firms to hire people cheaper. Instead, they've just limited themselves to the number of associates they can afford to pay 150k a year to. It turns out most law firms are astonishingly bad at the business part.

Simultaneously, clients have become less willing to pay for associates. When times were very good, they didn't care. Now, they care. They aren't willing to pay 450/hr for an associate to learn how to do a trademark case, they want a partner. They are basically willing to pay "nothing" for the associate until they've been doing this stuff for 4-5 years. Thus, the law firms are starting/continuing to have to eat that cost, since the still have to pay the associates, cutting into profits.

Cases like the Apple one are large cases. They often involve a large number of associates for a number of years, which, again, apple isn't going to be very willing to pay much for. The firm would actually be better off with simpler cases that associates can do multiples of at a time. For example, they'd be better having associates draft simple trademark licensing agreements for multiple clients all day, than taking on complex litigation like this.

"deep pocketed" clients don't really exist in the tech world anymore. It's true that there used to basically be a money faucet from deep pocketed clients, and you could bill whatever you want. This hasn't been true for a while in general.
They now all have very tightly controlled budgets for IP law in order to keep costs down. They are also pushing for and getting fixed cost structures from law firms. For example, they will only be willing to pay $4000 to a law firm to draft a patent, regardless of the size of the patent, complexity, etc. On the other side, however, firms are still paying per-hour billed. This can't last without driving per-hour salaries down, and it certainly doesn't turn into good money.

This is why "taking cases like this is not the way to do it anymore". It's no longer cost effective like it used to be, because the economics have changed.
It may work if you are a 1-2 person practice who specializes in this, and have very low expenses. This is also one of the reasons that NPE's have arisen. They have very fixed expense structures and take on a very specific set of work. It is, sadly, a very efficient way to work and make good money.

But of course, this doesn't mean the lawyers in this exact case won't make good money. They may, they may not, depending on how the firm is structured and it's particular financial situation. But it's definitely not guaranteed. It's also not a good business bet anymore compared to simpler work that you can get paid just as much for, or you can have predictable expenses for.

Note that none of this is not a very structured argument. I haven't sat down and tried to present a very cogent argument (that would take a lot of time), mainly just answered a bunch of questions and tell you are wrong. I wouldn't expect much else from a lawyer :)

That said:

TL;DR Lawyering as a profession is not going to be a high earning profession in the future until lawyers become scarce again. Lawyer earnings will only get worse. Law firms that think otherwise are kidding themselves. If you want to make good money, go into plumbing. Most master plumbers are over 55 now, and nobody is willing to send their beautiful unique snowflake to trade school anymore. I expect within 10-15 years plumbers will make 400/hr, and lawyers will make less than the average website design guy.