Lets suppose OP and few others ( non - DT members ) tag them, it wont hurt the accounts. Its only when the DT members tag the account, it matters the most.
When majority of the community members understand and practice the feedback system, it matters. Otherwise, for tag from non DT member, it doesn’t matter much to be honest. However, someone have to start. Today may be a few start practicing, tomorrow it can be increased. I hope you got the point.
Again, without sending valid feedback, you can't be a DT member. People will only add you to their trust list if they find your sent feedbacks are valid.