I have only read the first couple of pages or so of this thread so hope my comments aren't too similar to those of other posters.
I do understand why people get upset when they see their younger relatives and friends being unable to live in the area in which they grew up because prices have risen. However, prices rise anywhere where people see they will be more able to afford to move out to and live in.
The same thing has happened where I live in London. We bought in this area because, moving back to the south east from the north west after my husband obtained a new job in central London, it was virtually the only place we could afford in the London area. We have eventually benefitted because we bought relatively cheaply for the area (though not for us) and our house is now quite valuable. That's good news for us and all the, mostly older, people who did the same and have paid off their mortgages. The cheapness of the area has, though, over the years attracted more and more people from areas nearer the centre of London like Hackney (which is now very trendy and expensive) and, consequently, has substantially pushed up prices here. It has also brought in more money for better local amenities - new sports centres, upmarket bars and shops, etc. That's good news for us and all the, mostly older, people who did the same and have paid off their mortgages. However, younger people on low or even average wages - unless they get significant family assistance - can't afford to buy here now, and can hardly afford to rent either. So they move to the outer edges of London or even to a completely different area. Some friends of ours who work for charities, although in their 40's did not have a high enough income to buy in this area, although they'd saved a substantial deposit. They have since moved back to where they were brought up - in the Midlands. No doubt, others are moving out to similarly more reasonably priced areas, and are gradually pushing up the prices there too.
I do understand why second homes are frowned upon in small, sought after communities but surely actually living in an area is different. My Mum lives in a small village in East Anglia. We moved from outer London when I was in my teens - and we weren't particularly welcomed by the locals. But, despite a small estate and larger homes at the edges of the village being built some 30 or so years ago, many of the amenities are now disappearing. Only one pub, when there used to be three, a not very good bus service and no buses on Sunday, one very small village shop with only the very basics in stock, a butcher and a post office, the future of which is in doubt, and a comprehensive school in the next village which has in the past been reported to be near closure. Plans for another smallish estate at the other edge of the village were strongly opposed, some years ago, as was a proposal for a nearby country visitor centre, which would have provided some local jobs. Yet people complain about the lack of investment in the village, disappearing amenities, etc. They can't have it both ways.
When people talk about their "indigenous communities" or, like a taxi driver I spoke to who referred to "London rubbish" moving into the area he had moved to from London (the hypocrisy!), I agree with Anja that no wonder people from further afield are disliked when people from this country are also not welcomed when they move to a new area.
Iwonder if those people who are so opposed to properties being sold to "incomers" would put their money where their mouths are if they wanted to, or had to, move away. Would they turn down a quick sale and possibly an inflated price and only agree to sell to a local? If not, they are hypocrites.
Yes, there are good and bad "newbies" - but there are also good and bad "oldies". And whether they be old or new residents, they are all subject to market fluctuations caused by issues outside their control.