I'm not sure they would, actually.

It's been my experience that there are several clearly recognisable personality types and work ethics in a typical software development team, with two groups in particular that always stand out.

You can have people who come into work, do a decent job, and then go home and spend time with their kids and other things that really matter to them. The job isn't something they live for or feel deeply invested in, and they are unlikely to go "above and beyond" on a regular basis. They welcome training to develop their skills and will consider new working practices with a reasonably open mind if a good case is made, but it is up to the company to arrange and manage such things. However, the bottom line is that these people do competent work to a reasonable professional standard. In my experience, this is by far the largest category in most software companies.

Then you have the geeks, the ones who love the work, spend a lot of their spare time programming as well just for fun, follow all the latest trends, and -- dare I say it -- often frequent forums like this one. It is in the nature of this group that they will learn and develop their skills faster both because they spend more hours programming themselves and because they are exposed to more diverse influences within a shorter period of time. These people won't be the ones waiting for the company to organise training, they'll be pushing to get the latest book or go to a useful conference, or they'll be giving the training themselves to share with their colleagues some new ideas that they've discovered elsewhere. The risk with the younger members of this group is always that they will go too far: while they can be many times more productive if properly guided, almost all architecture astronauts, latest-shiny-development-process evangelists, and similar poisonous influences fall into this category as well. The risk with older members of the group is that their priorities in life may change, often as they have growing family commitments, so even if the desire is still there, the time to keep up as much as they used to may not be. You can usually recognise the ones who manage it, because they'll be the ones who somehow manage to help half a dozen different colleagues to solve some non-trivial problem each day, even though they still get their own work done faster than most anyway.

In my experience, everyone in the office knows which of these (or other) categories everyone else falls into within a few weeks of working with them. The former group don't tend to begrudge the effective keen ones the faster career advancement and more rapid pay rises they tend to achieve, because they recognise the difference in approach. On the other hand, they also have little time for the keen-but-poisonous ones, and become mighty upset when someone who thinks they're all that but isn't really generating the results to back it up is being mistaken by management for one of their more productive brethren and rewarded disproportionately.

In short, there are different types of people and they know who each other are. As long as reward and career advancement are based on genuine merit, I don't think most older "journeyman" professionals do begrudge the young high-fliers their faster progression.

(Edit: As an aside, I assumed your examples were exaggerations. I have never met the 25 year old, my egotistical self included, that was worth a senior job in a larger development group, even if they thought they were at the time.)