Yo, I love varying my characters' ages. Allegra (my fursona) is 4, and I actually have a warrior cat who is 6. I once had an elderly wolf named Mordecai who was 11, as well.
Although, my warrior cat, Lightmare, has been called "elderly" for being 6 years old, when in reality, that's just barely scraping into being middle aged. Talking in human years, she might be more along the lines of 35 or so.
It annoys me a smidge, but I also remember that most people make these 1-2 year old characters because they want to create a new story with them. Get them a mate during their prime, raise kids, lead a pack/Clan, etc., without having to worry about someone questioning their "strength" or whatnot because they are still young. It boils down to experience in roleplay, essentially, since the ultimate goal in RP is the story, including the character with its strengths and weaknesses that make for an interesting tale alongside other characters. Everybody wants the big, tough hero type, but not everyone is like that, realistically. There's the wisened oldster, the timid youth, the foolish and inexperienced young leader, and any mix beyond these. It makes the world you're creating more believable.