While I sometimes enjoy watching trailers for other films in the "bonuses/special features", when I buy a film (whatever the price), what I want is to watch the film:

I put the disc in the player, I press play a couple of times after I chose the spoken language/subtitles, and then, I watch the film.

Even if you can skip them, I really dislike the sequence of trailers, ads, "FBI WARNINGs", more ads, "enjoy the full experience of ULTRA HD", THX deep note, yet more ads.