Do you think actors are the only people who are involved in making a TV show?
There are also writers, directors, cinematographers, cameramen, casting directors, costume designers, makeup artists, CGI specialists, video editors, composers, musicians, sound engineers, foley artists, location scouts... I could go on but you get my point. These people work fucking hard, they all need to be supported and they don't all get paid a shit-ton of money. The more successful a show is, the more likely that the people who helped make the show will find more work and go on to make more stuff that I like. Yes, I think this is a perfectly valid way to spend excess cash.