Well, here in the states anyway, this is what we call Capitolism at its best.
Certainly for some users, WMP has the functions that suit them, while others prefer something else.
Within MC, some users find tagging, DVD or TV features useful, even powerful tools, yet others use it strictly as an audio player, playlister and catalog system.
But in the end, the true test (ament) to MC is, they do listen, they care what their user base has to say and are usually willing to implement changes if the demand is justifiable. Microsoft doesn't really care if you use WMP since it's freely available to almost anyone and comes standard in a windows install. Their goal is to make Windows a necessity in your life, not just WMP.
In the end, if you find WMP useful for your needs, then so be it. Enjoy it.
As for the YADB issue, it just a'int gonna change in MC, man is that a dead issue around here. And the cataloging you mention is all customizable in MC beyond anything WMP can offer, but maybe you don't want to spend the time, I can understand that, so again, enjoy WMP.
A'int freedom of choice a grand option?
WP