I dont like having to pay landing fees at fly-ins if its just a small fly-in at a regular airfield, particularly where the airfield is benefitting a lot by extra custom, fuel sales restaurant sales, and particularly where the airfield puts little effort into the fly-in.
Most airfields dont charge when there is a fly-in. Some do.
I dont mind paying though when other organisations have put on a fly-in and have to hire the airfield and a lot of equipment to make the fly-in happen. Most of these events are the larger more interesting ones anyway. Similarly if its an airfield or a strip that has been opened up specially for the event.
A lot of the best small events at strips dont charge, but have good catering made by the locals offered at a reasonable price, but to make a profit and thus cover their expenses and perhaps make a donation to charity. You dont mind paying a bit extra if you know its good stuff and the profit going to a good cause, rather than buying grease burgers from the local rip-off mobile catering unit!