Even today, it seems the tokens from any airdrops are easier to be accepted in big exchanges. I don't know why this happen, maybe the airdrops are backed up by big companies/platforms.
It's more due to users, if project has lots of users, exchanges are more inclined to list those as high chances those users will come to the exchange to sell their airdropped tokens — more users, more profit for exchanges.
Primary reason why exchanges like Binance and Kucoin started listing tokens like HMSTR, DOGS, CATI — these tokens are no good, but has millions of users, I am sure they must have gotten plenty new registration for listing these tokens, as most of usersbase these telegram tap-to-earn games has is of average joes who possibly would not be having account on any crypto exchanges prior.
Also, It's not a big deal if things don't work out, as they can simply unlist them later on, but makes a lot of sense from the business perspective to list them.