Are we certain this doesn't happen to locals as well? Also, did this "restauranter" not sign a lease/contract with the property owner? Surely he wasn't just winging it with the property his business was operating on. Prices will go up as cities develop...and especially when the inflation rate was up around 6%+ for most of 2018. (It is down to reasonable levels now, 3%+, but it is not unreasonable to think your rent will go up along with everything else.)
This happens everywhere - I know someone in Ireland who took on a new pub, sited next to an estuary, and over the years built up the business to where it was highly successful. At the next rent review the owner of the property increased the rent so massively that he could not continue and ended the lease - the owner now runs it himself. It does not seem fair to take away a business that someone else built up but that's life.
Yeah, but you could make it really expensive for the property owner by completely stripping the bar of everything that made it resemble that successful bar. Certainly don't leave the kitchen/bar equipment, tables/chairs, inventory, decorations, and basically anything else that wasn't permanently attached to the structure. Make the landlord pay out the *ss to reopen in that location you spent so much time getting people to like.
The owner is a millionaire landowner - he would not care. The prime asset is the location - on a very beautiful estuary. I think he intentionally let someone develop the business for him to take it back eventually. I almost had this happen to me but I anticipated it and had two nearby sites where I operated my business from - I made it plain to the owners of those sites that if they decided to go it alone I would use the other site to put theirs out of business (the cost would have not mattered to me as long as they failed) and it worked. But with the pub (converted from an old farmhouse) in a beautiful location there is unlikely ever to be another one nearby.