I on the other hand agree, with the "soured the franchise as a whole" argument, though not in such stark terms. I'll bet almost everyone who is an active Star Wars fan saw Solo in the theater at least once. What we are dealing with here is the nebulous whims of the casual viewing audience. They go see the numbered films and it doesn't take all that much to throw off the momentum. If TLJ left them with a not positve feeling when the left the theater, even if they can't define why, then their Star Wars momentum may have been disrupted enough to wait for Solo at home. I saw Solo in the theater. My wife waited until the home release. Similarly, I saw Jurrasic World in the theater, but I didn't bother to see Fallen Kingdom. I'll catch it at home when I feel like it.
Yet here's the rub, post showing audience ratings for TLJ were sky high, as were early Rotten Tomatoes scores. The evidence suggests people generally
didn't leave the cinema feeling the way you describe, at least not on the scale the argument would require to hold water.
On the contrary the evidence points to there being a
later shift in perceptions
which correlated with the increase in online aggression towards the movie. That's a totally different scenario and fits entirely the model where the TLJ "backlash" was artificially manipulated and this study is an eye opener because suddenly a lot of the missing pieces of the jigsaw now seem to fit. The discrepancy (which I'm far from being the only one to have been pointing out for months now) between initial positive reactions and later controversy now makes a lot more sense if there was an active involvement in manipulating "the mob" and there's ample evidence and precedent for how easily that can be done under the right conditions and this all fits together very neatly.
SW as a whole is simply too big a franchise, too ingrained into our culture and with too big an ardent fanbase to literally be brought down by bad reactions to one film, the prequels have shown us that
Solo though was a completely different beast to TLJ and has all the hallmarks of having been due to
individually fail anyway. It came out on the coattails of two much bigger, better marketed releases in a season that was already saturated by the sci fi genre at the time. It was so poorly advertised and marketed and so late in the day that a major segment of the general viewing public weren't even aware of it's existence, much less in a position to evaluate it in relation to another film.
It should by rights have been a major success, but it was mishandled and badly timed and that would have scuppered it without TLJ. It's simply a question then of applying Occam's Razor. If we have a perfectly workable set of hyoptheses for Solo's failure, why reach for unfounded and speculative explanations which don't fit the data and are clearly ideological in origin?