Yes, I didn't google but I think there are plenty explorers for Bitcoin.

there is many block explorers,the problem would be the huge amount of online wallets that people have in blockchain
it would be catastrophic

Thats why you don't put too many coins on a site like that. Haven't we learned our lesson yet? dont give any site, I don't care how trusted they are, the private keys to your coins. Now, its a nice place to have a little bit of coin for easy spending, but I wouldn't hold over a coin there. Plus if you back up your wallet and use 2Fa, you should be okay, even if they were to go down as you would have the .json files.

https://blockexplorer.com/
http://btc.blockr.io/
https://www.biteasy.com/blockchain/blocks


But Blockchain.info would instantly be up on many other TLD's just like what happens when governments try and block torrent tracking domains.

Their wallet is actually open source and the source file is available on github. As long as you have a recent backup (at least as recent as the last time you generated a new address) you would be able to simply recreate a similar service from their source files and import your wallet from your backup.

Other options would be to use your backup to import your wallet file into one of many other options to use as a wallet

I think that will be the best advice that you could get. Back up your wallet.

Then use other block explorer. You don't really think that if blockchain.info fails or the owner forgot to renew the domain, it's going to cause bitcoin to fail as well? It just extracts info from our blockchain and presenting in a nice format to see. Nothing beyond that unless you are telling me you are keeping all your coins there