I like what you are saying and agree with you. I have taken a deep dive into the tribes and noticed a couple of things that make it worth posting from their interface. The main one is for SEO value. Because of duplicate content issues when trying to rank your post in google for whatever reason you may be trying to do so, Steemit will defer the link juice to the tribe interface. So posting on @steem.leo will be the recognized first content in the eyes of google. But, if you post on steemit, steemit gets that honor and the leo post will be duplicate. That will be important in the long run for steem and the tribes. The second reason, and this is for @steem.leo in particular is that if you post directly from their interface @leo.voter will upvote your post in both steem rewards and leo rewards. That is flying under the radar at the moment but it shows that steem.leo is trying to add value for its users.