>not a valid reason
ok mr my opinyun is objective
Well, being old doesn't actually change any of the things about the phone. It doesn't change how it looks, or what it can do, or how well it does it, or the build quality, or anything tangible. If you don't like it when it's old, then the only logical conclusion is that you also didn't like it when it was new.
It is possible that you simply like newer products more, but that isn't the same thing as hating the old one.