Comment by hathawsh

I actually agree with this. Product designers and product managers are often essential and sometimes they do up to 99% of the work of figuring out how something should work. To accomplish that, they often do things well outside the role of a software developer. On the other hand, in my experience, only someone with a software development mindset seems to be able to complete the last 1% (or 10%, or whatever) that reveals and resolves certain kinds of logic issues.