Its like saying, oh you like your power steering, and automatic transmissions? Well then you couldn't drive a Model-T.
That viewpoint that progress makes you weak is a very bad way to view the world. Progress makes us all better at what we do by making us more efficient.
No, I think it's more like saying "most of those efficiencies are probably cargo cult" especially since programmers with just a 12" laptop and Vim can (and do) run circles around people with double and triple monitor setups and fancy IDEs.
So nothing especially efficiency improving that wouldn't be trumped by simply more skills.
(Not saying that you don't have skills. You might be better than Linus. Saying that multiple monitors are not the reason for that).
Yes, it's nice to have a big screen, but not really essential. As for the second screen, it gets all marginal returns from there.
It might be convenient, but hackers for decades had just had 14" (or less) monochromatic monitors and they've built masterpieces on them.
If "dual 27 inch monitors" are so important to your work, then (a) I don't see how you'd be able to be a programmer in the 80s and 90s when those things either didn't exist or costed a fortune, (b) fine, don't travel.
The "very heavy" part (for the 17" laptop) doesn't matter, as you're not supposed to backpack everywhere with it. Just keep it at your hotel/rent house/bangalow in the different cities you visit and work from there. You can still visit the city and explore all the other hours.
Besides, if it's that important, then anywhere you go and stay for a month or more (and nomads can spend several months on each country or more), you could buy a $200 24" monitor -- and then just give it away to some friend you've made, charity or sell it.