The usual argument is that by imposing an artificial ceiling on price, you cause the quality of the good/service to drop (in this case, you make rental properties worse) and you prevent people from selling it (in this case, you prevent owners from offering up rental properties, causing rental property to become scarce).
To claim that something is great, you should at least address the standard arguments that it's bad!
To claim that something is great, you should at least address the standard arguments that it's bad!