Blocktivity is a website where you can see the number of daily transactions (tx) which are happening every day on different blockchains.
The reason for the delisting of STEEM is unknown.
BUT: He listed HIVE instead!!! So the owner of the blocktivity account probably hates what Justin did to STEEM, or he even thinks that HIVE has successfully replaced STEEM.
Screenshot is taken from https://blocktivity.info/