If you buy agricultural land, you don't have to continue the plots there

Lol. You are clueless here - clearly you know nothing about real estate law.

If you buy agricultural land that someone else leases, you have to honor the terms of your lease. You don't get out of a contract just because the property changes hands.

Similarly, if you buy a company you cannot hire the employees.

If you buy a company, you still have to honor existing employment contracts.

This whole discussion is ridiculous because it happened a hundred years ago and then no one would bother with such things.

Yes they would. Real estate law is centuries old at this point, and well established.

You are judging people of another era by modern moral standards.

And contract law didn't exist 100 years ago?