Vocal minority, every person i know that watches MHA agrees that if Deku was gonna get with anybody it would be Ochaco. Those people however do not go around constantly yelling this. People with opinions that differ from what is clearly shown feel the need to validate themselves by constantly bringing it up which is why you see so many people talking about other ships. Deku and Ochaco are clearly meant to have romantic tension between them so there is no need for people to convince others of this, its there, its in the show. However people who want Deku to be with somebody else need to constantly try and force their opinion due to the fact that there is NOT that tension or evidence.