Would it honestly matter though?
To quote one Charles Matthias Punk, "Vince is going to continue to make money despite himself." Despite the dwindling ratings and viewership, WWE continues to make money hand over fist. Like other niche industries, they've mastered maximizing profits from an increasingly small base. You said it yourself; wrestling is as uncool and culturally irrelevant as it's ever been. But that doesn't mean it isn't "popular," and it certainly doesn't mean there aren't a lot of people willing to spend money on it.
Fans have done about every gesture of discontent one could think of. They've booed or remained silent. They've done hashtags. They've made signs. They've ranted online. They've cancelled network subscriptions. Many have actually followed through on their threats to stop watching; hence dwindling ratings and attendance numbers. They've walked out on the main event of Wrestle-fukking-mania. More than once!
And.....nothing has changed. Instead, WWE has responded by: increasing the number of shows they do, taking PPVs network exclusive so those fans that are left have to pay them if they want to watch those shows (unless you're pirate gang), expanding their merchandising, going into other media like film and Youtube, and, most importantly, expanding more into foreign markets. Bascially, WWE saw upset fans and, rather than improving or updating the product, they just did what they had to ensure they'd still get the bag.
So when I see people chastising fans for not doing gestures like this or not booing Vince, I have wonder why you think it would matter. WWE doesn't care what we think. I have never seen a mass market product show as much open contempt for its audience as the WWE. This is the same company that did a storyline where Bayley was made fun of for being a wrestling fan....and lost. In fact, she not only lost, but she was fukking embarassed to the point she'll probably never get back to where she was. We got wrestlers out here calling fans entitled babies for not liking the show, getting into arguments with viewers on Twitter because they dare to criticize booking or the show. Every time fans react in a way the company doesn't like, the wrestlers go online to complain and company doctors the footage so it never happened.
So were the audiene to show up to Raw on Monday and turn their backs, I have full confidence that all that would happen is Vince would insult them and then we'd have to endure Seth Rollins, Road Dogg, and whoever the fukk else going online later to call the crowd disrespectful for not appreciating all Vince has done and blah blah blah. If it hit mainstream press, then they might do something with it as an angle, but that's it. Nothing about the overall direction of the product would change because none of the high ups feel like it needs to change. And if we keeping it 100, they're right because they're still making money.
At this point, if you boo or rant online or turn your back to Vince or join #NoWatchGang, it's not going to be as part of some grand protest that will one day lead to a better product. It'll be for your own peace of mind.