Maybe because with ANH no one was really expecting anything? Alien3 had to top Aliens so i could see the pressure being on. With Blade Runner i think it was probably just too weird, but luckily we have the director’s cut (and like 8 other cuts), it is almost hard for me to imagine the original ending and voiceover now. I had to rematch it on youtube.
And then of course there was this alternate ending that never made it:
In the end, the movie could never hold up to the complexity of the book, but I still think it is a great film, especially given the context of the time.