I would use glass bottles to feed my kids, but I always held the bottle because the glass gets incredibly hot. I would wrap a towel around it to make it safe for me to hold.

By the time they could hold their own bottle we used plastic both for safe surface temperatures on the bottle and in case they threw it or dropped it as you mentioned.

The milk doesn't need to be that hot. Warm is fine, and if the bottle is that hot, I'd worry that the milk is too hot to drink.

I'm a parent and we are feeding our second child from glass bottles because of microwave+micro-plastic concerns. So far no bottle throwing, so we'll just see how far we get with these until the throwing starts. We'll probably also switch to glass food-containers for daycare once he starts going there.

They sell silicone bottle wraps that basically eliminate this concern.

So far, glass bottles have been fine for my kid.

I was guessing the commenter was referring to the expense of buying glass bottles, because they cost about double, and that "literal nightmare" was hyperbole.