Buying altcoins is pretty much only viable if you look to bank on short term movements. If Bitcoin shows up with lightning network, the purpose of nearly all the altcoins in this industry will then be largely gone.

Altcoins won't have the advantage of offering "cheaper and faster" confirmations anymore, which will make a lot people flow back into Bitcoin's ecosystem. It's a logical happening, really, and one that makes sense.

Bitcoin as we speak is a solid long term investment, which can't be said about altcoins with the aforementioned in mind. It's up to people to make that decision for tthemselves, but at least think about it in a serious manner.