I don't know them all....but "Follow the money" is an universal true expresion in all cases, so let's enjoy the fact that we have what we have, and let others bother about all the rest.
Imagine if osclass wouldn't have been around even in the shape that it is..... the IT bussiness is a wealthy one, so the people that work @ osclass must be payed. If you include all the new good ideas into the free core who will buy the plugins? How would they pay their people that are working on it?
You start understanding more things when you have, say 1-10-20-300 people that you must pay each month.... their families don't care about what they do at work..they only care about the money, so that they may live.
Now comparing wp with osclass, their purpose are different. WP has a wider usability that a classifields has. It's like developing windows vs linux in the games' behalf. You can't play games on Ubuntu so that's why windows is winning here.