Let me ask a counter question: Why would you want to store more? And what kind of data would you want to store in the blockchain that can't be stored any other (better!) way?
Additionally to the above:
Why would you want to store that data on the bitcoin blockchain instead of a different one?
BTC is a currency. The blockchain is the public ledger to store all verified transactions. Why would you want to store unrelated data there?
Despite the fact that a blockchain in most cases isn't even the best solution.. why should it be the BTC blockchain?