Striking a blow at affluence (or the appearance of) is probably a secondary consideration/added benefit.
Bill won the Dem primary partly on appealing to PETA and other animal rights fanatics, who WILL vote single issue, by promising to get rid of the carriages.
Keep in mind that the real danger (or, to non NYC Conservatives, the benefit) of Deblasio is that he’s in no way beholden to the wealthy Manhattan Liberal power elite which would otherwise act as a political check on his extremism.
Yeah, my guess is that when he decides to go whole hog on his ‘War against inequality’ and it goes unchecked, billions will leave the city, and tens of thousands of jobs, and pass the popcorn, please.