If you are asking about http://Strimi.pl/ the answer is: because Strimi.PL is not migrated on to Steeem yet.

In other words, steem-based version of Strimi is not ready yet, nevertheless we decided to inform you, that we are working on this and when we will finish, we will replace old strimi with new (based on Steem) version. Then, few thousands of current Strimi users will join Steem eco-system.

We are going to publish frequent updates about progress of our work :)