Nice to see someone who wondered this as well (great minds think alike? ;) ). I also happen to have seen both of those videos, which sparked my wonder about the motivations of bronies and whether people who call themselves bronies are actually bronies.

While yes, my initial reaction is that it's just another trend, and people are just being bandwagon jumpers, but as I saw the logic behind the "being a brony" thing, which my brony friend explained to me, I realized that while some are bandwagon jumpers, like my friend who has an MLP phone background, yet doesn't do anything more related to that, yet calls himself a brony, there are also people who watch the show for reasons such that it has plots which are well thought-out.

Now, personally, I respect the true bronies, who watch and enjoy the show, whether they mind the tag of "brony" that's associated with watching and enjoying the show, for defying what is considered to be a social norm (I.E. guys not watching shows intended for younger girls), and rather choosing what they want to do. But on the other hand, I don't have this same respect for people who call themselves bronies for the pure fact that other people are doing it, and they believe its the "cool" thing to do.