I would compare that make your own client to capitalism, where as if we were to force everyone to release everything so the field was completely level would be loosely like communism.
There we have the whole "FOSS is commie" discussion again. 
I think the use of which FOSS license isn't so much of a deal. I mean, there are a lot of licenses that fall under the OSI definition. And MIT is not so bad. I normally put my software under the GPL, because I like the fact that it is copyleft. But if another dev thinks an other license is better, who am I to judge (I didn't write any code for it). This is the same discussion as GPL vs. BSD (MIT being almost like the BSD license).