I have to see an episode of this and see what on earth all the fuss is about... From clips it looks awful, but I think the majority of modern programmes are awful and you can't really judge by clips, so that means nothing...
However, I find nothing wrong with adults - male or female - watching cartoons. My husband and I bought DVD sets of some of the cartoons we watched when we were younger (90's versions of X-Men, Fantastic Four, Spider-Man etc. and watched episodes of other things on YouTube, including Arthur lol... I love Arthur hehe). My husband's uncle, who is usually into Zombie films, also bought DVD sets of children's programmes from when he was younger.
I think most people, if they felt free to admit it, would actually like to watch cartoons... But we're brainwashed as a society, into thinking that cartoons are for children, unless they're specifically aimed at adults... When in reality, there are plenty of cartoons which have far better character and plot development than many programmes aimed at adults... To the point where many people who do watch cartoons end up thinking of themselves almost as rebels... I don't, because well, it's hardly rebellious to watch a cartoon - but some people obviously do... I'm sure part of the "Brony" thing is about rebellion in the minds of some of the men...
However, I think anyone getting so obsessed with anything that they go and collect items obsessively and get dragged into the culture surrounding whatever they're obsessed with is a little weird... If it makes you happy, then that's great - don't stop, there's nothing wrong with that... but realise that people will find it weird... Which, in itself isn't a problem at all - it's only a problem if people react negatively to perceived weirdness.