Let's not forget that land lords have a huge investment in the property that they would like to make even 1% back on in rents.  Factor in non paying tenants and destruction of the unit well above the deposit and quite often you make nothing.  What no one has mentioned here but Natalie I know you know is that the renters tax credit is probably less than 10% of the amount the landlord has to pay (4.5%) on the rental "income" to the state.  So for a $2000 per month rental the landlord is paying GET of $90 per month to the state.  Does the renter get $1080 back from the state as a renters credit?  
so the state and federal are once again making unearned money from the landlords investment in money and time.