I noticed way too many examples of sexism in Equestria, so I will lay out most obvious of them.
1) There are no mares as taxi 'drivers'
2) No mares as guards.
3) Heck, they didn't show any mares who did something physically exausting. As if they aren't capable to do that, or something.
4) Female characters shown weak and almost useless (for example, crying scenes. In the majority of cases mares were the ones who cried.)
And overall, they show female characters as pathetic and useless weaklings who can only wear fancy stuff and paint their faces (Sweet and Elite for example). But of course, I'm sure that I'm the only one who noticed all these signs of discrimination. I mean, no insulting or anything, but bronies tend to be sexists, most of the times. Well, obviously not only them, but I'm talking about this fandom now. Hovewer, I still apologise in advance, if someone found this insulting. It's just an observation.
But back to the topic. There are also many other signs of discrimination, as in putting female characters in stupid situation, showing them as complete retarted idiots, making them unable to handle problems themselves (season 4 premiere and finale) and so on. Honestly, even games don't discriminate females as MLP does. Take Skyrim for example -- they play an important role in this world. But I'm sidetracked once again. Sorry, my bad.
Why am I posting it? I don't really know. Probably because I'm trying to attract at least some attention to this problem and make them understand, that this discrimination exists and flourish. If not... well, I tried at least.