Apart from scam artists in crypto space we have too many unprofessional developers that falsely act like they are really good in a particular field and try to build blockchain based projects but failed in the end,if there is really any way to make blockchain available to only professionals that are qualified it would have been a different story for crypto,even scammers wont have a chance,this is why i think we need REGULATIONS pretty bad.
Having a certified blockchain developer would still not stop scammers from doing what they need to do because a blockchain developer will not filter the project he is to develop, he will only be consulted to develop the project which they might not even know the intention of the business owner, so they will simply do their job.
The only major part where I would agree with you on having certified pro developers is the aspect of low quality projects, we have so many low quality project that if we had the touch of a professional developers, those project would have been the talk of the town, and with a qualified developer, we would always have projects with real use case being released. These are part of what should really form any regulation policy.