Yeah, A New Generation and Gen 5 basically killed the MLP fanbase, and MLP as a whole has basically died an inglorious death. Though, to be fair the last few seasons of FiM were getting long in the tooth, and "Gen 4.5" in Pony Life was their last attempt at squeezing what was left out of Gen 4.
Hasbro fucked up and unintentionally killed the golden goose -- Ironically, people were more interested in the awesome new art style for the FiM ponies at the start of A New Generation than the actual movie and its plot/characters themselves.
A lot of people were also theorizing that Gen 5's setting is basically a post-apocalyptic version of Gen 4's future (like you see in a lot of Zelda games), but interest in that basically died off when the connections between FiM and aNG/Gen 5 were basically even far looser than Zeldas' games' sequels/prequels, lol.
I hear basically nothing about Gen 5/MLP these days, and I hadn't thought of it until you brought it up.
Man, I remember back in '12 when the whole Canterlot Wedding thing was going down, and people were going nuts about all the new lore/story stuff that Cadence and Shining Armour introduced (as well as Celestia not being an actual god).
Times have changed...