Interesting ideas.
I think something like this, shared through targeted advertising on social media (targeting WP users, generally,) could both confirm the value of the things we’ve been working on (ie, they want it to be faster, they want less breaking changes, they want less cruft,) and it could also reveal things we’ve not yet considered or have overlooked.
Survey monkey has a few plans to choose from https://www.surveymonkey.com/pricing/individual/details/. It looks like the Advantage Annual plan might be a workable option at $384/year for unlimited surveys and up to 5000 responses per month. I’m not sure what kind of action it would get on social media (or the cost to run a campaign), but, that seems (to me) to be the easiest place to target the right users. Just a guess; I’m no marketing guru. 