While I would like you agree with your logic, I have some serious objections:

According to my own personal typing model using colemak should yield the following benefits (assuming you type exactly like me):
- your fingers travel 45% as much
- you type slow, awkward combinations 69% as often
- you type fast, super easy combinations 22% more often
- based on the change in slow and fast combinations alone (not counting distance at all), your speed will be 13% faster

Additionally, Colemak balances the hands and does other things in attempt to reduce injury or increase speed.  It's unlikely they are all useless, and because you have only reached 60 wpm on either of them it is likely you simply are more familiar with one than the other, as you have "mastered" neither.  I believe this is a better explanation than the one that QWERTY and Colemak are equivalent in quality.

For similar reasons I once in a while intend to (temporarily) switch back to Qwerty, too.

When typing plain text, I can still use Qwerty pretty effectively with few mistakes, but I'm using a lot of keyboard driven programs (vi, mutt, ...) and for those it's a real pain as muscle memory seems much stronger for single-key commands (and those can't be "backspaced" easily), so I usually just give up after 5 minutes and revert to Colemak. :-)

I find alternating between Colemak and qwerty much more comfortable in the long run than using either one or the other exclusively. They use different muscles in different ways so when one of them gets uncomfortable or tiresome I can just switch back to the other for a few weeks. I've been back on qwerty myself for the past three weeks or so, but this is unlikely to be permanent.

Bombadil - I thought in late 2008 you were just learning to touch-type, and learned in dvorak and then switched to colemak  ( https://forum.colemak.com/viewtopic.php?id=542 ).  Where did touch-typing in qwerty fit in there?

maybe you'd notice a more worthwhile change if you were proficient in either layout. i type at an average of 130wpm at 89% accuracy in qwerty. i'm hoping my accuracy will increase in colemak, due to a decrease in row hoping and finger stretches

I think that an important point here is that switching to Colemak has a cost even beyond the sheer effort of learning it in the first place. Sure, you may well be saving miles of finger travel every year, but you still have to live in a world where QWERTY is the norm, and you'll still encounter QWERTY keyboards on a regular basis (phone keyboards, other people's keyboards, etc). On top of that you have the hassle of installing Colemak on machines where you want to use it, and dealing with Windows seeming to arbitrarily switch between keyboard layouts whenever it feels like it. All these little things add up to a ongoing penalty that QWERTY users do not have to pay.

Now you may argue that this is a small price compared to the ergonomic nirvana offered by Colemak, but that is definitely a personal judgement. Clearly using modern keyboards with lightweight key pressures, many people manage to type using QWERTY at a very high speed and without too much discomfort. For these people the minor hassles associated with Colemak may outweigh the benefits it brings.

Furthermore, using portable solutions such as PKL there is no need for installation and even on my work computers I'm only a Ctrl+Shift+2 click away from a smooth transition between QWERTY and Colemak (and when I log onto my work account I start in Colemak).

Typing a bit QWERTY is inevitable (I still haven't figured out a good and cheap Colemak solution for my PlayStation3 for instance) but that isn't a problem for me. Granted, I have to look at the keyboard more than I used to but the speed is good enough and I'm not confused.

It'll be a personal call, of course it will. Some people are life hackers and optimize their life as a hobby, others couldn't care less if they "waste" a goodly amount of time and effort on inefficient living and would rather be without the hassle of relearning things. Sure. But for the ones who do like to improve things I'll wager that Colemak will be worth their while!