Bad altcoins are important.   You could say that altcoins are like business ideas, startup ideas.  You need many of them, to have a few good ones emerge from time to time.  If only 'good' ones were allowed to even get some attention, that would be like stopping people from having the right to start a business on an idea.  You'd need some "state-approved licence" to be allowed to start a business: THE way to kill creativity, and to render the entire scene totally corrupt.
Investors know this: if you invest in 10 startups, most probably 9 will fail.  You're simply hoping to catch the 10th one.  But you can't know in advance.  So the 9 bad ones are NEEDED to allow for the 10th to develop.
I would say that it is reassuring that there are many bad coins.  It means that there are possibilities to make a good one. 
What is to be avoided at all price is that we get stuck with old technology (bitcoin) in a monopoly.  Such a monopoly situation is extremely dangerous (as every monopoly situation is).  Crypto can only live if constantly, new coins are created, value changes from one to another, and nothing is permanent.  Only when the rules change all the time, institutional sticky fingers can have no grip on it.
I'm also convinced that the only way to keep decentralized, is to have constant changing of rules and hence, constantly changing of "favorite crypto". 
Most probably this will only partly succeed, as most probably, crypto will evolve in a kind of exponential distribution of market caps.  Bitcoin will most probably stay number 1, but will become totally fiatised and institutionalised and in the end, centralized.  In China, I have the impression it is underway. 
But hopefully, there will be true crypto being invented all the time, and permitting true decentralized and ungrippable interaction "down under".