This is an opinion.  A correct one. 

In an age of Netflix and video on demand there are limited reasons to watch a movie anywhere but from the comfort of your own home, with a loved one (or alone) while looking at your phone.
The only reason to not watch a movie at home (or at a home of a loved one) is because the movie is only available in theaters.

Expenses aside, seeing a movie in theaters is a fun time out. It’s the thing you do after a dinner date or on Sundays. There are new-concept theaters popping up everywhere that serve you food and let you drink alcohol. Alcohol is good too.

Movies in the park are bad because:

Seats

You have to sit on the ground for longer than an hour, and strain your neck to see the screen. Humans are not meant to sit without back support for this amount of time, which is why we invented chairs. You can’t bring chairs to movies in the park because that would block other people. People will bring chairs to block your view because life is a rotating carousel of inconvenience.

Other people

Other people are generally bad. They have a tendency to ruin most things. They will quote the movie you are watching and laugh before the punchline. Some of them will clap during the film. They won’t even notice you sneering at them.

The movie

The movies that are shown in parks are “classics” which means you’ve probably already seen it or other people will make you feel stupid for not having seen it.

The outside

Movies in the park are usually scheduled ahead of time so it will be raining during the screening.

Food

You cannot order popcorn or make your own popcorn. You can bring your own food if you’re into spilling on yourself and forgetting napkins.

We are living in the golden age of content. There is no reason to gather together with a bunch of other people who have already seen the movie to prove you can laugh at the nuanced joke the loudest. This is the correct opinion.