The fear of a quantum winter is one reason---if any reasons were needed besides the truth!---why I've spent so much effort on my blog over the past decade trying to counter irresponsible QC hype. Like, if anyone ever comes to me and says "you lied to me! it turns out that scalable QCs are really hard to build, and a lot more basic science needs to be done, and even if you did manage to build them, as far as anyone knows they'd only give you exponential speedups for a few special problems, not for most of the stuff my company cares about," I'll have a pretty enormous record that I can point to when I reply, "I WAS SCREAMING THAT AT THE TOP OF MY LUNGS AND YOU DIDN'T WANT TO HEAR IT!" For all the good it will do. :-)
Then again, maybe the worry is overblown. Some people claim that we've now passed the point where there will never again be an AI winter, any more than there will be an "electricity winter." The train just has too much momentum. Likewise, so long as the pressure continues to get more and more computing power and stave off the end of Moore's Law, it could be that QC will continue to entice people, regardless of the naysayers and regardless of how hard the engineering problems turn out to be.
I honestly don't know. I feel like I have a hard enough time understanding and communicating the truth about where this field stands in the present---and sometimes, trying to advance it by a small increment---without also prognosticating its future. :-) The latter involves all sorts of questions of economics, politics, and psychology that I have no special expertise about.