Let's be honest, T2 ended perfectly. There really is nowhere else to go with this franchise. Bringing back Arnie and Linda Hamilton might make it slightly more palatable but we already know it won't be as good as The Terminator or T2. The only story left to tell was that of Kyle Reese being sent back in time. That would have been interesting.
Just the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.