Holding Alts is not dangerous, as long as their roadmap is not crippled. In fact, altcoins in some cases are more profitable in the short term than BTC as they show relative 2x, 3x, ... 10x within short periods of time. Bitcoin can only jump that high once in a while and then come down again. But this alts have a remarkable way of surpassing one's expectation, catching you off guard.