Yes, I do POS it self is not the problem. ETH is planning itself to become POS coin. Either way, master nodes coins share the rewards between POW and MN. The rewards can be split anyway % wise and POW can last indefinitely is developer wishes to do so.
Proposals of masternodes sells by scams so often, they says: "buy 1000 our coins, build MN and get profit", then they take a money and do nothing. Therefore many users avoid them. It can affect the development of coin negatively.
I can counter with that the same happens if the developer of a regular POW coin stops developing or vanishes. Nothing is stooping a POW coin to be a scam. There plenty of POW coins that faded to obscurity or were some sort of scam.
Yes, you are right. POS itself is interesting solution. But I said, about that for many users POS associates with scam, and this lowers the trust, especially for new coins. By the way, ETH is not ready to turn POS even, and no one can say for sure what the final decision will be.