We have been told several times that Steemit,Inc has contacted Coinbase on numerous occasions about listing steem.

"contacting" them isn't enough. I'm betting all of those other tokens have been putting in serious biz dev work to make it happen. Steemit, Inc doesn't have any business development people even on their staff. If I were them I would stop all the ad sales stuff and focus all of that energy on business development deals such as Coinbase.

But I don't realistically ever expect them to do that.