Yeah it’s the logic of “soft” xenophobia (we don’t hate foreigners, we just treat them different!)
Tax-evading PR holders are a small percentage of a small population (so not a big problem). But, for unreasonable reasons, perfection is demanded of outsiders that is not required of insiders, and the entire problem is blown out of proportion.
There are already laws against evading taxes that could be enforced without applying a special, nuclear-level punishment to PR holders.