Spey guys, yeah, but that's mostly because of the length of the rod. Glass gets heavy in longer lengths, and you'd have to be a glutton for punishment to cast a 12 foot glass rod. (Although I do own a glass switch rod.)
No problem with bigger fish or flies, though. Back when I was a teenager, I'd sometimes cast the smaller sized Hula Poppers with a 7 weight glass rod for bass. (Not the best use of either a fly rod or a Hula Popper, but I wanted to if it could be done) and I still cast deer hair frogs with glass from time to time. A few years ago, Lefty Kreh wrote that the guys who need a 14 weight rod prefer glass, because they're less fragile than graphite when you're dealing with 400+ pound fish.
Still, it's a matter of personal preference, and it seems you prefer carbon.