If for no other reason at all - why would you want to eat cows that were treated cruelly when you have a choice not to?
Because I'm very poor and grain-fed is cheaper, for example? What you're saying is very valid, just a bit off topic.
This guy says there's no evidence that grass-fed is healthier, it isn't much tastier, nor safer, which seems very much in contradiction to the experiences here. Personal experiences are most of the time fuzzy though, how do you know if it wasn't just a placebo effect, an effect from something third (e.g. was the problem the instincto diet, or the grain-fed meat, in TylerDurden's case; did his health improve significantly later because of switching to grass-fed, or because of being longer on raw diet), etc. I'm continuing on eatwild.com it seems like a pretty comprehensive collection of related research.