I would say that it's okay to trade alt coins but it's not okay to trade new alt coins. Most new alt coins lose so much of their value in days and the ones who invest in those alt coins might end up losing their capital, but the reputed alt coins can be safe for trading. I personally trade Bitcoin and some alt coins and so far I have made profits with both Bitcoin as well as alt coins. However, the profit that comes from alt coins is higher than that of Bitcoin in my case.