Good advice.
Using an alternate cryptocurrency client would be a great way to get many people to install a hidden virus that targets Bitcoin users.
If you have a significant amount of Bitcoins, I wouldn't run other clients on the same computer until the alternates have developed trust over a longer period of time... I'm probably on the paranoid side of things though.
These new cryptocurrencies are interesting, and it will be fascinating to see how it will all play out.
Meaning to say that these altcoins can infiltrate our privacy and stole our bitcoins? In order to be safe, we should be aware of our privacy and we should first test the reliability of the altcoin circulating the internet. In that way, the altcoins wouldn't be a destruction to us.