Renters don't do "nothing." Part of the job of these rentiers - through the profit motive - is to allocate property to the highest (most efficient) economic use: someone who wants that land has to show that costs (which represent the value other people place on alternative uses) are less than the income, or the value people place on the proposed use. So they have to show that their uses is the use that satisfied the most values. Basic price theory.

Then, they get money from rent if they successfully allocate this land. If they unsuccessfully allocate it they have an incentive to undo that mistake (evict) and try again next time - and those who are really good at allocating well get more resources.

Now, whether the ones that "got there first" should get land is a good question, but it really doesn't apply in a market, since those who actually have the best record allocating land resources will end up with more land, no matter the original distribution. I would like to ask though, how else should we initially allocate propert?