Personally, I consider my dog and cat to be pets. Regardless of the dictionary definition, by the literal definition I can actually "pet" them. I have trust in them that they will behave in the way that I have trained them (i.e. sit, stay, use the litterbox, etc.) and that they will not harm me at all. Sure, my cats scratches sometimes, he bites, but all in play.
I love snakes. I always have, and always will. I have not made a single penny off of an animal, simply because I have never sold a single animal. At this point, I am PURELY a consumer. I keep my animals in the best condition possible, and they are all doing well. However, I do not trust any hot, or any snake for that matter, to behave in the way that I want it to. If I had a gaboon (I don't), and I stuck my hand in it's cage everyday to change it's water bowl, without any restraint on the snake (I'd be an idiot), and it never struck at me, the next time I stuck my hand it, it very well could. Just because it hadn't before, it doesn't mean I trained it for anything. Bottom line: You can NEVER trust a snake, venomous or not! They will never be trained, they will never have any affection for the keeper, and they will be more than happy to kill you and not have a single regret about it when your turning all sorts of funny shades of blue on the floor.
That to me keeps them from being pets. Don't get me wrong, if my house were on fire, I would make a valiant effort to save all my animals, venomous or not, even if it put me at a greater risk than I'd like. I may not succeed, but I sure would try. I love my snakes. However, for me, calling a hot a "pet" makes me cringe. If you want to call them that, it's fine, but it just looks wrong when someone posts a message saying "look at my new pet cobra".
As far as the whole "domesticated" thing goes, the dictionary might say one thing, but the usage of the word in the real world generally means an animal that has been accustomed to human interaction. If I went out and captured a wolf, and brought it home, it would not be domesticated by most peoples standards. It would still be WILD. And yes, a snake produced in captivity is still a WILD animal. Dogs are DOMESTICATED versions of wolves. Wolves are NOT domesticated.
Okay, I need some coffee. Sorry to rant for so long, I surely didn't mean to. In any case, pet or not, I really don't give a crap anymore.