Grew up in the rust belt of Michigan, but not with parents holding unionized jobs, and still live elsewhere in it (also without a unionized job). Can't say I've seen the same sentiments or patterns be as common as presented. Of course I've always leaned towards supporting unions so that colors the perspective a bit too, but, in general, approval of unions in the US has actually been in an upswell
https://news.gallup.com/poll/694472/labor-union-approval-rel...There are obviously areas with decline for sure, e.g. the auto industry, but unions are usually seen as lessening the impact of that on the workers rather than the source of blame (not that everyone holds a single view). E.g., for the most part, people don't blame the union (or non-unionized industry) for the problems in Flint as neither is meant to privately fund e.g. the water pipes. They blame the downturn of the auto industry, which then gets into whatever reasons one prefers to assign. For some that's unions, but it's not actually been a very big mind changer on that aspect.