Well, I'm kinda like you man. Back on OSI and other shards, I rarely used animal taming... so when I first started on here I didn't use it either.
But to answer your question (to the best of my ability), there are some on here who are quite capable w/ out the use of pets. I seen a certain few melee Paragon Ballies, which IMO is whacky

. A lot has to do with the gear you are equipped with, and since there are quite a few AWESOME pieces of gear to be acquired on here, it is very possible to be a "non-tamer" on here.
Now, on another note... many shards have a Skill Cap. On Excelsior there is NO skill cap, which means you can 120/130 every skill! With that in mind, it might explain why many have went to Animal Taming as a primary means of killing MOBs. Also, if time/efficiency is taken into mind, having 5 maxxed Nobles/Mules/Imprisoned Pets do your dirty work frees you up a lot more time and makes killing things faster; thus allowing you to maximize your playtime efficiency.
Sorry went off a bit there. That being said, you don't have to have Animal Taming on here at all. Get yourself a Tome of Nature (ie: Druid Book) and some rocking armor, and youll be quite capable going solo.
Rarr!