I don’t think we’re ever going to get the full story here, and none of us have seen the contract. But just because something’s legal, it doesn’t mean it’s ethical. I don’t think anyone’s suggesting that Merlin or the council have broken the law, but booting someone out of their business at two weeks’ notice doesn’t sound like a very kind thing to do.
Again, we don’t know what legal advice Graffiti Golf have had, but I can imagine that some people leasing a mini golf aren’t going to have access to a top legal team. How was the contract presented to them? When I leased a flat a few years ago the contract was 130 pages. Just because they signed the contract, it doesn’t mean they fully understood it. For example, they might have been told, “This is a standard contract. You need to sign is ASAP or we’ll lease it out to someone else”. Of course, they may have carefully explained the contract and pointed out all the disadvantages. It does sound a bit dodgy though.
Where you’ve got a clear imbalance in power, contracts often are unfair. It’s like telling a farmer to stop complaining about the super market, because they signed the contract. When a much bigger and wealthier party is making a contract with a much weaker party, it doesn’t seem right for the bigger party to take advantage.