The sprites have changed because the times have changed. The new generations just don't appreciate the novelty of 2D static sprites, all they do is whine about these newfangled 3D sprites. To keep the peace, Pokemaster conceded to have every sprite changed to the Gen VI animated ones.
But this really is an open-and-close case, er, question. The fact that the new sprites look "crap" is a matter of opinon, and in a broader sense we really don't care. That sounds super snobbish and mean, but consider the reality of the situation. The Pokémon Database isn't primarily a Q&A site (although taht is a big part). I t is a database. People outside of our community use it for resources. If the site still had Gen V sprites, it would start to look outdated and old.
TL;DR We use these "crap" sprites to make the DB an up-to-date and appealing internet resource.
