I think it's less of the first an more of the second. It's not senior vs. junior but younger vs. older. It also, IMO, has less to do with age and more of generation. When my parents were growing up and entering the workforce, they did so with parents that grew up in homes devastated by the depression. Companies offered pensions and that was guaranteed money for life (at least for the most part). Their children (my generation) grew up with pensions becoming less popular and a big press for 401(k)s. That generations children have heard nothing good about pensions, only how they go under and people don't get their expected retirement.
Since those who are from the earlier generations grew up with the concept of pensions they are typically more comfortable with that. In addition, it's more difficult to get a decent retirement out of a 401(k) with only a short investment period compared to a pension. The 'youngins' today favor a 401(k) because they don't get turned over to the PBGC and don't rely on contributions after retirement, whereas pensions do. Because they are younger they are also able to bulk up their account with decades of contributions. Just to put it in perspective, I'm figuring that in a perfect would when I retire from working like in about 25-30 years I'd like to have approximately $4-6 MILLION in savings. Will I get that? Probably not, but it's actually not completely unrealistic to do with decades of contributions; to do so with maybe 10 years would be impossible.
Pensions and 401(k)s are completely different investment strategies, with their own benefits and drawbacks. Only a fool picks one or the other if offered both, and only a fool will depend on others to invest their money or themselves (unless actually qualified, few are) to do the investing.Having the IAMNPF managing my pension is great; in theory they will be far more successful and reliable in managing that money to ensure it's there 50 years from now. Having a 401(k) allows me to play a little, and even still I invest in mutual funds with fund managers that are far more qualified then I. One backfills the other and winds up providing many layers of redundancies.