Think about what it means 'their land'. The people have agreed that they will protect his exclusive right to use that land. They gave him a set of rights associated with it. There are other people these days for which there was no land left - thus making a price congestion for the existing land.

Shouldn't the current owner pay the tax as means of 1) congestion pricing and 2) service fee for others guaranteeing his rights?

It feels to me like a fair tax as you pay for what you use.