Good question.
Cobinhood because anyone can fill out the form. Most exchanges require the CEO or active manager of the currency to fill out the form.
HitBTC because they have already listed both STEEM and SBD. The problem is that they have broken wallets (down for "maintenance") for many months now making their exchange unusable for STEEM and SBD. All they need to do is fix the wallets.
I will find other exchanges that are willing to cooperate with regular customers.
If you know of anyone on the Steem platform, you can try to convince them to fill out the Kucoin exchange listing form.