Agreed, that retirements on other fields will yield a marginal increase in the aggregate wealth accumulation potential for the younger generations. The effect on 121 ops will however not be as dramatic as most people HOPE it will be.
That said, my beef with the boomers is that by delaying their own retirements they are forcing me to start capitalizing at an older age, therefore sliding my income producing years to the right in ways that all but cement the need for the younger generation to work past 60. The only alternative I would have is accepting a lower quality of life and attempting to retire before 60 regardless of what my economic condition is at the time. Most people will unfortunately default to feeling "forced" to continue working past 60 as they set out their economic expectations on benchmarks of 20th century bubble economics, which will all but disappear from the American landscape circa 2040 (when Gen Y starts reaching the classical definition of retirement age).
It's not looking good for the home team (and I'm not talking about the boomers....), but if you're able to lower your expectations in wealth and retirement, a decent living could still be had in 2040 America. As it stands however, nobody got into the "borrow for education", six figure debt between a degree and a mortgage racket, to end up having to downgrade their life expectations. That is the biggest wildcard in the future deconstruction of our society. I see a lot of bitterness and lashing against boomers once Gen X fully ages and Gen Y starts retiring. Grandma boomer is going to have a rough last decade once she breaks the budget on her medicare and SS while the kids do without mcmansions and toys...and retirements too. That said, I do welcome the departure of the boomers from the workforce, good freggin' riddance and wishes of a Merry early Xmas...