You know, I'm not really the type of person who looks down on others for enjoying childish things...
But I will say I've hesitated to pick up Amiibo multiple times because, well, I do basically see them as more or less toys. Toys with some added functionality, yes (but nothing mind-blowing yet I'd need them for), but ultimately just toys. And when it comes to things I enjoy, I'm a really pragmatic, non-materialistic sort of guy. I buy the video-games, obviously, because that's an entertainment medium with an obvious function, but my fanship stops pretty much there. I don't really collect any outside stuff like toys, figurines, cards, etc., because to me there'll just sit around gathering dust. Hell, a lot of games I own do that as well, and I always feel a sense of "am I wasting my money buying these games I only play maybe for a few months?"
I picked up a Donkey Kong Amiibo, and just because he's an easy to obtain one, a character I like, and I just wanted to see its Smash functionality at least once. But besides probably getting around to picking up maybe Link for the HW Spinner when I get back into that game when I clear some of my backlog, I don't intend to buy anymore at the moment unless an Amiibo function seriously catches my interest. And so far, they haven't.
But I don't harbor any ill-will towards people who collect Amiibo, and if I was in a better financial situation, with a solid job, I'd probably be a much more avid collector.