I've never experienced any 'episodes of frustration'. But that doesn't mean they don't happen I suppose. I've always found it to be a very welcoming atmosphere... but I've also never tried to do anything that might be seen as 'overtaking' or taking advantage of the situation.

Cornwall itsself is a pretty insular place, where the people are proud of being specifically Cornish. I imagine a lot of people are quite bitter that most of the money in the county comes from rich outsiders coming in for their holidays.