Well sone alts probably will have their time of getting a decent value. Well alts that does have value today, those that are in the top 10 or top 15, are a good investing prospect. I do hold crypto aside from btc. Trx, btt and recently i bought a bag of ripple. Looking at the short term, these coins may not be that attractive to crypto investors but their projects makes me think they'll have a good decent future.
there is a big difference between value and price (profit).
what you are talking about regarding altcoins is the profit you can make from their price going up and down that is usually referred to as pump and dumps. but it has nothing to do with their value.
value of a cryptocurrency is defined based on the utilities it offers and since altcoins lack utilities and the only use case of them is for trading, they have no value.