CoinMarketCap has the power - many people looking into that website on a daily basis, some even on an hourly basis. This gives huge traffic into it. With this move I sort of feel that CoinMarketCap want to "monetize" their traffic.... I know I know, they are already doing it with adverts, banners on the top, on the side etc...
But remember the price tag, of listing the coin on the Binance, some speculating that the price tag is 1 mln USD. So why not Marketcap to actually get paid for the thing they do, and we all know they do it the best in the space! (most popular coin market capitalisation site in the space).
This is just my opinion, where all this "vote for coin listing" might be going.