I think the difference is that softwares are developed and tested against the windows translation layer. Then open source community try to recreate this layer on linux in a open source way. In the long run it probably will become better and more powerful than the windows one, but it needs time and more problem are expected in the first iterations. 

 The first iterations were in 1993... 3 decades ago 

 great part of this kind of softwares are rewrited every year. Its a matter of fact that unless 4-5 years ago mainstream games on linux mostly didnt work.