No, it's not logical because it requires you to ignore many things to make this connection. If a child is watching a show, the parent will see it too and will often watch it with them to share in it with them.
Parental Bonus is a bonus. The main content of the show (the characters, situations, settings, and plots) are still aimed at little girls. Each episode will contain a few parent bonuses just to throw some bones to the parents.
I've watched some child television with my niece who is 3. There's no parental bonus in Dora the Explorer. It's boring, but my niece loves it so we watch it so I watch it too. MLP on the other hand is much more bearable thanks to parental bonus. However, the plot (of the one I watched) was still about making matching dresses for a dance or something like that. If you're not into wearing matching dresses, why would you as a grown man by yourself watch a show about that?
It comes down to this: you can like MLP if you want. That's fine. You can like watching a show about matching dresses and you can like matching dresses yourself. I don't care. But let's not kid ourselves. Let's not lie about why you like it. I see two options: you either like little, girly things; or you like being part of a "counter cultural movement thing" and this is an easy one to be a part of.