The problem with crypto in general is that there's no valuable mainstream execution yet. I do believe in the intellectual merits of crypto currencies but when you buy a particular currency is a speculative guess on whether or not that particular coin will achieve mainstream status.
It's as simple as that. Bitcoin itself is a foundational coin so it only will cross the non-speculative line / fad bubble until at least one other crypto coin becomes mainstream (it's capable to completely supersede a FIAT currency use case like remittances)