Exactly. It is actually a very good comparison I think. When you buy a bunch of domains and squat them without doing anything with them you are paying the "tax" but have no income. It is actually in your best interest to develop a business on your domain to compensate for the costs.
Just like land tax would do. Squatting a bunch of land would cost you a lot. It is would be in your best interest to maximise income from the land to pay for the tax.