I recommend you to read this post: http://apforums.net/showthread.php?t=43324
If you are not satisfied with the anime, I think you should blame all the stakeholders except Oda, not only Toei. Nothing would ever change if One Piece was done by another animation company, and things might be worse. In fact most animation companies even don't have the abilities to make a long running show lasting for at least 20 years.
I have read it and its very informative. Thank you for putting it out there, But i don't think that justifies or excuses what Toei is doing.
Pokemon and Detective Conan started before One Piece and they still manage to put out consistently good animation, Its not perfect but consistently good. What is the difference between them and One Piece?, I'm pretty sure One Piece is on bar with them in terms of popularity in Japan and make a lot of money for the investors. The only difference between them and One Piece is that they have a good studio that handles their properties better and care about viewers. You would think having two of the biggest anime in the world DBZ and One piece that are licensed all over the world, airing on tv and having them on streaming websites that they have a lot of money to improve their their anime, hire good animators and will only put out great quality anime because it reflects them as a company, but no apparently they don't care. Replacing the studio with a better one is the only solution that I can think of.