That is a very good suggestion. My own opinion is that it should be decentralized. Each SMT should be it's own kingdom, and this means the creators of the SMT should be able to activate the suggestion you mention or not. Some people for instance could create an SMT to specifically do reputation in the form of a token system where the non-transferable token represents reputation. In fact this could be based on the design I contributed to, featured in the Bitnation whitepaper: https://github.com/Bit-Nation/Pangea-Docs/blob/master/BITNATION%20Pangea%20Whitepaper%202017.pdf
Reputation could be important for all trades. In fact, Bitconnect has a reputation system too if you were not aware. So they figured that part out and their reputation is a "collaborative filtering" Ebay or Amazon style system but it will work well from what I saw. Not only that but Bitconnect has the ability to remove abusers from their system, or cut suspend accounts.
In my opinion, I think we have to be careful giving the ability to remove rewards to the democratic process. People get jealous and will remove or attack others for petty reasons which have little to do with anything legitimate. So I think while a reputation feature should be an option, it should not be mandatory for all SMTs. This way people who aren't popular but who clearly can add value to Steem can do so through the SMTs which don't require it.
The goal is to get as many people to add value to Steem as possible and leverage different skills. Diversity of talent exists and if we find excuses to kick people out it does not increase the network effect (network effect is connection between the people) and this network effect is shown to be the true wealth of our network.
Keypoints:
Observe from Bitconnect that their mission is the exact same as Facebook, to connect the crypto community. Consider also that Bitconnect is willing to change or improve it's policies when they discover it doesn't work or is not sustainable: https://bitconnect.co/system-news/65/members-of-bitconnect-are-informed-about-policy-change-in-bitconnect-affiliate-program
And eventually to this: 
The other thing they did really right, their website has some of the best marketing I've seen in the space. Well designed site, the pictures describe the programs so well even a 3rd grader could grasp it. Honestly Bitshares and Steemit are not anywhere near as well explained so a lot can be learned about explain a referral program in plain language from Bitconnect as well.
So the more we connect people together, and the more opportunities we give people to earn a profit by their unique talents, the more the economy will grow, the more people will join, the bigger the reward pool for all. In my opinion a permissive and welcoming community has an easier time growing than a heavily restrictive community.