I stand by my use of the word regressive. I use many cross platform apps; this is the only that has this restriction. Many allow just two instances on either platform; that is a restriction that seems fair to me.
Mac development is happening - as is windows development - whether a windows or mac user, respectively is using both or not. The comment about "paying extra for Mac development" makes no sense at all. If I install five copies of the windows version, are four of them "freeloading" on development? It's software, not hand-carved wood.
Bottom line: it's the way it is, logical or not.