Not saying that landlords need special treatment, but they should not be penalised.
By imposing higher taxes on rental, you're telling property owner to forget about renting, just leave it empty until a buyer comes along, hence flipping. Rental properties are already paying higher property taxes, you are suggesting even higher property taxes. The signal you're giving is that you should only buy for own stay, don't buy for rental, but it's ok to buy and sell.
Fine tune taxes for initial years? So higher property tax for 1st year, lower for 2nd year, and so on, that might work. So super long term landlords are encouraged while short term ones are not?
So the options are. 1) quickly flip to avoid rental tax or 2) be long term landlord?