This premise was very far off, and cost effectiveness is key to the design rationale - do you think this impacts upon the utility and attractiveness of Loki?
The rationale still holds and one of the primary reasons we built Loki is to have a an easy to manage scalable "open-source" solution.
I personally have been told to log less at a previous company because of the associated costs of logs and I don't think I utilised anything beyond grep (with a few exceptions). I personally feel the trade-offs are right and a simple greppable/tailable solution that is cheap is missing from the eco-system.