In beginning of 2018 there were a lot of alcoins was launched in market, Most of them was just to scam people with typically referral method by social influencers.
This was also a flaw of Ethereum blockchain where any single person can create his own coin with his desired supply and name by costing very low fee.
As with the help of Ethereum blockchain where it was super easy to generate any coin it was easy to launch any ico with high promising goals and convince people to make their money multiple x.
Those scam or ordinary platform make alt market dirty game. And this impact very badly on the genion project where many traders lost their interest.
You described it as if the big problem with cryptocurrency is that it is open source and therefore anyone can create their own cryptocurrency. Because of this, a lot of fraudulent and worthless coins and tokens appear. This is not a disadvantage, but an advantage of cryptocurrency. It is thanks to free access for everyone that cryptocurrency is developing and improving very quickly. If you limit access to it to create new types of them, there will certainly be abuses by those who will decide at their own discretion to allow someone to create cryptocurrency or not.
Potential investors simply do not need to rush to invest in all the coins and tokens that are rising in value. That is the problem, but it is an individual problem.