Comment by necovek

People have differently sized hands too: with my fingers on the home row, 13" and 14" Macs have the heels of my hands resting exactly on the sharp bottom edge.

Glare from the screen can affect you more if you have problems with halos in general (many vision problems can cause them, and fatigue won't help either), causing reflections to disproportionately affect legibility of the screen for you.

Finally, the keyboards are simply bad in comparison to best keyboards (in terms of typing feedback) on small portable laptops like Thinkpad X1 Carbons (though those have gotten significantly worse with Gen 7 onwards too).

Additional gripe I'd have is that they are very heavy in this day and age when we are getting laptops under 1kg (2.2lbs) in 14" size that perform and hold battery adequately well. This only hurts if you travel a lot and carry more than one laptop with you (business and personal, for instance).

But really, ergonomics is hard because everyone is different, and as long as you are outside the 2 SDs from average (and you can be so only on one of those measures, like your hand size or torso height or head size), your ergonomic position might be impossible.