Volatility itself is neither good nor bad.

For a speculative user, volatility can indeed be good if they're lucky to buy and sell at the right time. However, don't fall into the trap of "trading knowledge": in most cases it's really simply luck. There's one exception: Bitcoin's adoption rate could be predicted a bit, so the long term growth rate can be "exploited" by HODLers. It's however also not guaranteed that Bitcoin's price will continue to increase.

But there's a problem with Bitcoin's volatility in particular, exactly because it could limit Bitcoin's adoption by the masses. A purely speculative and volatile asset will never get used as a means to save money, much less as a "P2P cash". Money is most often saved for unpredictable situations (like job loss, sickness etc.), and you can'trely on that Bitcoin's price will be high when you need your saved Bitcoins.

Fortunately Bitcoin's volatility is lowering already. But it should be at most a third of the current volatility rate, very similar to the volatility of gold, to become really ready for mass adoption. If the current volatility trend continues, however, it's possible that we'll reach gold's volatility in 5 years or less.