My biggest problem with new pokemon, outside of re-used concepts like you mentioned, is the way they are made.
Most gen 1 and 2 pokemon have a solid design going for them, simple and memorable, based on an existing animal (or a combination of one with something, like mashinery), has a leading colour thats subdued enough to not look ridiculous, basicaly, they looks like they could exist in an actual eco-system.
Druddigon here is just a mess of random shapes and bright colours. So many new pokemon are now just a bunch of squares and triangles and circles with ultra-shiny reds and blues and yellows in a vague shape of an animal, like its a Picasso painting without intending to be one (and even THEN that idea was already used much better on Porygon). Either that or its a re-used idea, like another bird pokemon, or another moth. There are some good ones, sure, but so many of them just look so friggin ugly, ugh.