I've noticed a lot of people have a problem with fluttershy for the reason that she never seems to get over her shyness.
But I'm here to defend fluttershys honor.
Being someone with social anxiety I can completely understand her fear and why it isn't easy for her to get over it quickly. And even after an episode targeting her shyness she goes back to being shy. I think her improvement is happening at a good pace and if they rushed it and she just suddenly wasn't as afraid that it would be unrealistic.
Maybe I'm biased but I'm curious about everypony else's opinion on this topic.