Actually, weight and their increasingly absurd pricing are the only reasons I switched away from Thinkpads. Then there's also availbility issues (I believe this is a problem with the Dell XPS models as well). Still, I believe they offered solid Linux support out of the box, if that is what you are primarily after.I considered Thinkpads too but they're usually too heavy and have crappy displays. Definitely nowhere near the quality of LG Gram with a 1440p color accurate, high brightness 16:10 display.
The thinkpads which have good displays cost well over 1L for half decent config. And of course they tend to be quite heavy.
They're good laptops, but not without compromises.