why don't people like helicoiled bolt holes in intakes

I have seen several ads and posts that make a big deal about the bolt holes not being helicoiled in an intake manifold. I don't get it. I've had many manifolds that have carb stud holes helicoiled and even one that had the themostat housing holes done and never had a problem out of them, what gives???? Some of the coolest manifolds haven't been made for 40 or 50 years.