I haven't lost that much experience to respecs, but I've lost millions of gold swapping heirlooms. Gauntlets, body armor, weapons, horses, etc. Often I'll change it up just for one or two generations then change back to what I had before, losing a point in the process. I'm just not patient or greedy enough to do well on the marketplace, I'd rather take a loss of 300k to get that specific item that I want, and to get it NOW.
Not to mention when I deleted my old main character, who had four +3 items... even after ~12 generations on Legs I still haven't recovered.