The 'proper' salary for a job depends on the productivity of the job. It is perfectly possible for a low-producing the job in Switzerland to be too low paid for natives to want to do it, and yet well-paid enough for immigrants to want to come do it. This is what the GP was alluding to - barbers and cleaners and builders and nurses are all dominated by immigrants because they are hitting the productivity wall.

The locals are mostly workers, not capitalists with companies and salaried workers, so it's not "locals" exactly.

Looks you forgot yours at home. Lowering expenses (so wages) in a competitive free market works exactly like doping in cyclism: you'll be forced to if you want to stay alive.

But even without considering that, the business-owning "bourgeois" class not caring about their nation has no reason to be left unchecked by those whose job is to run a country.