I think Fourth of July has more specific music/ foods/ decor than Halloween, which is usually for kids or a reason for college kids to drink where people throw 4th of July parties into adulthood. TV shows probably like it as a way to change up the characters, but there are horror movies premeiring all year round, so that's not even really a "Halloween thing."

Christmas has a lot of traditions and managed to get the Hollywood treatment, so that along with most people having time off from school and jobs, so there's actually time to relax and reconnect with family and friends compared to other holidays where you don't get time off or only get one day. Plus, it's easy to see the "magic" in it, which lends to the movies and TV part.

Things that are fun to kids are also often more marketable, so maybe that's why they get the appearance of being more popular, because there are more targeted commercials selling costumes and gifts and made-for-TV movies? These opinions are just from my experience, of course. If someone wants to throw an Arbor Day get together, I'd be there just as fast as any other holiday party, haha.