a lot of people care if you shell out money to see a show lets say to the great elvis presley and jimmy ellis shows up pretending to be elvis won't you be a little steamed.....
Once again, Sin Cara doesn't talk and you can't see his face. The reason you watch the character is the ACROBATIC and DAREDEVIL MOVES in the ring.
Therefore, if those moves are being performed virtually identically, week after week, who cares if a different guy is under the mask.
You forget that most wrestling fans don't do the website spoiler thing. So, they don't know who the initial guy, playing Sin Cara, was in the first place.
And, the reaction of the fans tells the story. The new guy, replacing the one who got suspended, got just as big an ovation from the people.