I have been paying for Resharper (and now Rider and DataGrip) for over fifteen years. Some companies where I worked paid for it other didn't but it didn't matter. It improves the quality of my code and I believe it gives me a competitive edge. It also helps keeping me sane as I work with a lot of legacy code.

I see it like a construction worker that uses his own tools instead of the broken down ones of the site. It makes good business sense that I can work faster and better when I use better tools. I also pay for other tools such as dbForge and SmartSvn/Git but Jetbrains' tools have been the longest running ones (I hope this does not sound like I am a fanboy or something).