It's an interesting thesis, to say that law has failed because people believe so little in the law they see no reason to even make their intentions clear in a legally common manner.

And let's face facts here : he is right.

1) a common person making open source code cannot reasonably assume he will enjoy the protection of the legal system when others violate the licenses (just look at GPL enforcement efforts and their lack of results)

2) the power of the law to enforce these things in the first place is very limited. If you don't notice the abuse yourself (either because you do, or because it's pointed out to you), the law isn't going to do so either (this is in fact an important legal principle in western law : if no-one cares, it's not against the law, not even if there actually is a law against it. Note that in criminal cases the state can "care" in a legal sense, on behalf of someone else (e.g. a murder victim), but this cannot happen in civil cases. This becomes obvious in the case of contracts, for instance: feel free to violate contracts ("commit fraud"), if the other signatory to the contract agrees with your actions. I will advise you to get that agreement in writing though)

3) you can make mistakes which get you into hot water. For instance, if you accidentally relicense, or appear to relicense, code from a large company, that can get you in serious legal trouble.

4) in practice, such massive portions of the law are ridiculous and unenforceable, and these portions have expanded, and expanded, and expanded yet more over time. Effectively, following the law is not a realistic proposition, and nobody should be under the illusion that they're following the law, ESPECIALLY when facing the police, but also in all other cases (remember this when the police asks you questions. The answer is always the same : I refuse to answer except through my lawyer (and even then, take the fifth). Why ? https://www.youtube.com/watch?v=6wXkI4t7nuc )

You should always treat any situation as a negotiation. Even when there is a clear law against what the person you're talking to is about to do.

I remember coming to a law lecture. The professor had 3 bottles of Bols (a famously strong alcoholic drink in western Europe). Why ? Well, the case he had started in his second year of law study against the telecom monopoly had completed, 45 years later. He had won. For 45 years of regular legal efforts, he got 83 euros (enough for 3 bottles of bols and some fast food). It was extremely nice of him, but it really drove the point home for me : the law, by itself, is merely an argument in any negotiation, and not a very strong one.

So we have established:

1) the law will not help you against others, at best it will enable you to help yourself (for a price, not for free)

2) the law may work against you. Taking legal actions, no matter how small, is something you don't understand (not even experienced lawyers or even judges can understand their everyday actions in a legal sense). Adding a license is definitely a legal action you don't understand and is not risk-free.

And I would add that this is plainly visible:

3) a LOT of people openly violate the law in pretty much all aspects of life (as a tenant which recently changed apartments, I was yet again reminded of this last month, getting charged with replacement costs for consumables, which was explicitly mentioned in the contract, and in law, to be the landlord's problem. Mentioning that got me a 50% reduction in what I got charged, and I accepted. Realistically I would have accepted a 10% reduction in what I was charged)

So why would you put licenses on your own code ? Don't. It's a risk without reward. If you want to go on a crusade, then go ahead. Otherwise, just stay away.