"Easy" is relative. "Evicting" an airbnb'er once the term is up will always be orders of magnitude easier than kicking out a long-term tenant who regards that as their actual home. There's not even anything necessarily wrong with this! The easiest way to address the issue is literally to slash any remaining red-tape that's making things difficult for those who would want to AirBnb these properties out, while managing the resulting side-effects (including the plausible effect on the long-term rentals market) by levying a special fee if necessary.

As a bonus, easy AirBnb rental provides an alternative for some who might otherwise want a permanent holiday home.