The rich people owned that land already. The poor leased it.

It looks like the rich only owned it because it was gifted to them by the crown - and the crown only owned it because they took it by force. Maybe all this was legal but only because the laws were bad.

Actually, in lots of areas of Scotland local chiefs willingly became feudal lords gaining "official" title for their lands.

...became feudal lords gaining "official" personal title to their clans' lands, IIUC.

Exactly - what was communal became personal. Which if not legally theft was certainly the moral equivalent.

aka rich people stealing land from poor people.

The aristocracy run the army, get a veto on the government, own most of the land and are rich enough to bribe god. Those enough reasons for you?