How much is Drake earning this year compared to Tannehill? How much next year? How important a position is the RB compared to the QB?
Drake is under performing, but as mentioned, he's relatively young and untested.
Tannehill has had more than enough time. The excuses need to stop. Salguero and Beasley made a good point. Even people who like Tannehill claim he needs everything to be right. Good protection, good play calling, good run game, good receivers etc to be able to be good. There are plenty other QBs out there who can be effective for all that. Do we even know Fales can't do it, with everything right?
What we need is someone who can make plays when things fall apart. And as we're seeing with Ryan this year, that doesn't appear to be him.