It might sound so weird and funny but i totally believe that all the stakeholders which you listed are equally all important on the steem blockchain....each of them all have their own positive impacts on the blockchain....
I believe the Steem community is the most important persons on the blockchain. We are all part of Steem and without us there is nothing.
Developers,witnesses,users,investors are all in this together and we need each other. No one is more important than the next person.Everyone fulfills a role in order for it to run smoothly.
I hope that makes sense,but these are my thoughts.
All you mentioned are necessary for Steem Blockchain to thrive, without them it's incomplete, oh wait.. I guess Steem would be fine without the use of bid bots.