You're right that a lot of the entitled screaming is ridiculous, but I think you're missing some of the very real problems that come with an influx of new money and (especially) second homes.
I grew up in a tourist area, and though I'm one of the ones who left for the Big City I keep in touch. I'll give you a few examples that I think are illustrative.
Immediately after college, a buddy and I shared an apartment in a nice building on a nice street. We both made decent money working in touristy restaurants, as did the three girls our age who lived next door (and, I think, the inhabitants of the other two units in the building, though we didn't have much to do with them: they were older, and had kids, so not much in common with us at the time). During the two years that we lived there, the family home directly next door sold. It was kind of sad, because a nice older couple lived there -- we watered their plants for them once, and the wife baked us an ENORMOUS batch of cookies to say thanks -- but the husband died, and the old lady moved away to live with one of her daughters somewhere else. Anyway, the house was bought by someone as a second home / investment property; during the next year it was used for exactly three days (for a really loud and obnoxious party, but whatever). We snuck in through the backyard to use the Jacuzzi a few times, but even then I can remember thinking that this place turning into an effectively vacant property was a bad sign.
Fast forward twenty-something years, and even more of the "family" homes on that street have become second home / investment properties. The four-unit apartment that we lived in is now exclusively rented out on AirBnB, displacing the service-industry families and twenty-somethings that lived there before.
Just about everyone who actually works in that town now commutes from miles and miles away, and rush-hour traffic -- on rural roads -- is terrible.
The displacement goes much further up the income scale that you'd think, too. I've kept my dentist there, partly out of sentiment: the dentist who previously owned the practice had looked after my teeth since I was, like, eight years old; my regular hygienist has been cleaning my teeth since I was about fifteen. I cleaned their office for them when I was in high school, and they still give me an "employee discount" on fluoride treatments or whatever, so going there gives me all kinds of good small-town feelings. A decade or so ago someone I went to school with partnered with the original dentist, and then bought out the practice when the old dentist retired. We've talked a few times, and I don't think it's gone quite as well as she hoped. For one thing, she has to pay her hygienists and dental assistants a premium, to keep them willing to make the fifty+ mile commutes most of them have to make, since local housing is out of reach. She expected that, though. What I think she didn't quite expect is that she'd have so many fewer patients than the practice used to have. Partly that may be churn that comes with the old dentist retiring and someone new taking over, but also it's because the year-round population has declined, and second-homers and AirBnB-ers aren't looking for dentists in their vacation town. My friend had expected to pay off the loan for the practice and then buy a home in town before her kids got to school age. It's now 8-ish years since we talked about that, and she's still making a ~70 mile commute each way.
Build more homes? Yeah: that does need to happen (I vote the straight YIMBY ticket in the city I live in, so I totally get that argument), but ... rural small-town charm drives the tourist industry around there. Build too much and you kill the goose that lays the golden egg.
It's a really multi-layered problem, that I don't think has a simple solution. That said, there are a few relatively easy things that I think would help a great deal:
1) Raise property taxes (how much? I don't know: double, triple, quintuple, octuple? What's a bigger adjective than that? It should be by whatever multiple it takes) on any property that's not a primary residence for someone. At some level it becomes worth it to rent out your investment or AirBnB property to someone who'll actually live in it.
2) Restore the train line into town (and probably electrify it, too), then run regular commuter trains throughout the day. The right-of-way still exists, and is currently used for touristy sight-seeing and dining trains. Those can still run, but they're terribly inefficient as the only users of the rails. The goal should be to get workers cheaply to work, and tourists off the roads.
3) Charge a congestion fee to anyone who still chooses to drive. I'd make it $300 for a permit that's good for a year: that hits the tourists really hard (and helps subsidize the train), but should be relatively affordable for anyone who works or lives in town.
I dunno. I'm not really arguing with you, but I do want to make the point that the economics of tourist towns are weird, and at least some of the locals' resentment is driven less by entitlement than by economic forces, and enforced changes, that really are hurting them.