if more newbie investors with no previous experience in other markets come in, that could be positive, BUT at the same time negative , if they get scared when coins go down, and they sell, because that causes coins to drop even more.

if experienced investors with patience start investing in cryptocurrencies that's good, they will be more patient, and hodl, even when coins go down, which keeps the market in tact.

However if superexperienced extremely wealthy investors enter the cryptocurrency market , and if they have intentions to pump certain coins, that's not good, because they could be manipulating the market.

So the answer is YES, and no at the same time!