I agree with you completely. While I don't think that XY were actually intended to be "filler" games (like some people here think), it really feels like GF is regarding them that way.
I think both XY and ORAS could've greatly benefited from a more drawn-out planning schedule similar to Gen 4. Like, release XY sequels (or a a very polished third version, ala. Platinum) in 2015 and then do ORAS in either 2016 or 2017. That way, Kalos gets a fair turn in the spotlight and gets to be fully completed and polished before moving onto the remakes (which, themselves, would've also benefited from more planning). SM would've been saved for a NX release around 2018-2019.