Yes, I'm not arguing that he's (edit: you're) wrong. Just that the decision seems to be causing people to choose other solutions, I suspect because managing one thing at least seems easier than two.
I think the threshold question will always be "Does software X make my life better?" and if it does not, you should ditch it if you can.
There is always a huge bias in reporting: People are eager to tell you why they started using your software, but they always forget the "exit-interview" when they drop it again.
The reason I hear most often for people dropping Varnish is that they have cleaned up the mess of legacy web-services, or at least transitioned it all to the New Fantastic Platform.
Other people drop Varnish for other versions of "this is now surplus to requirements" and I am totally fine with that: I dont want people to run Varnish if it doesn't make their life better.