If I will use your wallet, I will not need other wallets for different currencies?
And one more thing, if the purse of this project accepts tokens in the future. And then many crypto-currency wallets only one coin of the Etherium accept and the tokens do not work. It is very uncomfortable.
That's MEW wallet (MyEtherWallet). The use of ERC20 allows storing multiple erc20 coins in one wallet. Sure, it will be very cool when all your erc20 coins are on a wallet!
To get around the Ethereum, you do not just have to try and do something grandiose.