Provably because blockchain isn't really on top or a kind of wallet which people will recommend nowadays. They don't even have an option to recover a lost password of a wallet so it really isn't safe to use.
Before you talk maybe you should first do a little reading about the service so that you wont look ignorant. In what you wrote, you are wrong in both your sentences. Blockchain.info remains to be the top webwallet for BTC and the most recommended one at that.
Heres the funny part of your post that shows you are so oblivious and have not bothered to see the wallet.
They don't even have an option to recover a lost password of a wallet so it really isn't safe to use.