A core problem is that an influx of tourists hits the housing supply. Short-term tourism incentivises conversion of local housing to accommodate them (AirBnB, etc.) and long-term tourism results in foreigners buying local housing as their permanent or long-term holiday home.
The result is obviously a relative shortage of housing and rising prices, both of which make it harder for locals (who are often relatively poorer) to live where they need to. This pattern has been repeated from small villages in scenic areas, to big cities (e.g. Barcelona), to whole islands (e.g. Mallorca).
I’m probably one of the people that has contributed to this to some extent over time; and yet I fully understand the frustration of the locals.
It may result in apparent xenophobia in some, but its roots are rational and economic.