Considering 90% of crypto market's content is useless, I think the current statistics are really mild. If only 50% of altcoins have failed, it means there is another 40% under severe chances of failing as well at anytime! Investors must be careful and stick their funds only to a very select group of altcoins on this market in order to decrease the chances of putting money in altcoins which will return total loss for them on long run. Besides researching for the future predictions regards a determined altcoin, it's also important to analyze its past history, its features and potential next updates it's going to receive from developer's team.
Developers will have to stop creating projects as we don't need a lot of cryptocurrencies because what we need is a project that is usable and sustainable. Unfortunately, what we got is a bunch of shitcoins and scams which gives a reason for slow adaption and trust.
Developers should stop creating useless tokens nobody needs, however they keep doing this to benefit themselves, as somehow they need those tokens in order to make some quick cash over greedy investors who believe developers' false promises of returning hundreds or thousands of percentage over their initial investments. Most of these projects are copies of past altcoins, since they just reproduce the exact same features.