They're still 10x better than the 2nd best fighting group (Alloys). Yeah, I agree with you. What are they supposed to be? Animated crystals? Though I suppose the entire Smash universe is a little too original. Just look at Tabuu and Master Hand for final bosses.
The games made, no way to change it, I just play it for fun, not to find something to complain about. Alloys, Polygons, Wire Frames; They're not playable and they're just copy's of characters without their specials, How are they awesome? Because their Crystal/Wire/Metal?
The Fighting Polygons were the best because they represented every single character in the game in their crystalline form, sometimes altered a lot (Kirby looks like a cake, Yoshi has teeth), rather than a few characters.
They still only made 2 wire frames and only 4 alloys, which were a lot less than 12. Which means less variety. I'm pretty sure they can fit 30 something polygon thingies in the game. After all, we got (eww) Subspace Emissary.