I think a pension, like Social Security, is a great insurance policy, especially for the many non-Mustachian folks who never managed to get all their ducks in a row. While I'm not exactly one of those doomsayers who don't (allow themselves to) believe that their pension/SS will be there when they retire, I do prefer to focus on aspects of retirement planning that I can actively control -- like my 401(k), IRA, and Vanguard portfolio.
Not that long ago, I, too, was supposed to have a pension at a terrific job five miles from home that I could have done forever… That is, until I lost my (wonderful) boss to one round of layoffs, and then got hit myself a few years later. My next job had no pension (it was also in a different state, so my quality-of-life re: commuting was much diminished), and when I got an offer to cash out my old pension, I took it, because frankly, the offer itself made me doubt the solvency of the pension, especially since this is private sector.
I know that here on the MMM forums, there is a strong undercurrent of competition -- who can get their expenses lower, and their savings rates higher (no doubt fueled by sub-forums such as "Share Your Badassity") -- so you are inviting pushback by asking this question. But not everyone has the inclination to go to the same extremes, and a 20% savings rate is perfectly respectable and totally fine if those are the numbers that work for you.
As for myself, the main reason why I have a "massive" savings rate is because I made the conscious decision to front-load my savings to take advantage of compounding. FIRE wasn't even on my radar until a year ago, when I discovered MMM and ERE, so I'd saved aggressively for many years before that without thinking that I could ER. I think if you're comfortable with your career track, job security, expected pension, and financial projections, and you genuinely have no interest in ER, then 20% is well within the realm of normal, and if that's your own personal set point, then go with it. :)