Spoiler
I do have mixed feelings on it, which I am aware are hypocritical - I didn't like how they handled Tirek and The Smooze (or the Breezies, which are G3) either, and the whole thing had an air of "Not how I would have done it" to it, and still does. However, the hypocrisy comes in when you realize, that I have no problem with the Mane Six being completely different ponies to their namesakes (almost namesake in Twilight Sparkle's case), but I could argue that those ponies, and any other with recycled names, were just that, recycled names - even if any were meant as references (some were), they are supposed to be different ponies, but the other things I mentioned seemed to purposely put there as references, be it for fanservice or for the reason I would do it (or both.)
And why would I do it? Because I love the previous generations! And I love the idea of a new version acknowledging where it came from in someway, especially if it does so because at least someone involved in it is a fan (not saying the later writers of G4 were this), hence why (if you don't mind me dropping this in again), a project I am working on will contain several things, ranging from allusions to actual character appearances, from pre-FiM, even though the project takes place in Equestria.
I love doing that when I create projects based on things I didn't create (and I love doing exactly that, partly for that reason), and with MLP I'd have a field day (and I already do) - five generations, all containing at least one of the following; toyline, comics, books, and cartoons, each with their own canon to choose from? We're talking kid in a candy store territory here...
Also, Firefly was an accidental reference, but of course, the person they were referencing very likely chose her screen name because of her favorite pony... who was/is Firefly, so it's indirectly a reference, I guess. :silly:
Spoiler tagged, because it's long and only partly on topic.