I think yes, because many people use myetherwallet to stored altcoin ERC20 token because as we know myetherwallet is very convenient to use as crypto wallet but yes we need to be wise to use myetherwallet, avoid importing your wallet to many exchange sites because those sites is very risky, so its better to use secondary security to connect your wallet in the exchange if you want to trade your coins or to buy some coins in that way myetherwallet is safe.