Criminal is a big word, if you were around at the time Charlie was arrested you would know more about the reasons why he got arrested.
It was mainly for Fincen to prove their case before the bitlicence got put in place. He was arrested because he didn't have a money transmitter licence at a time when regulations were barely in place.
He was running Bitinstant one of the first bitcoin exchanges. The community at the time was very supportive of Charlie and still are. However newbies don't know this and only judge by what they hear around.
Mainstreet is not asking anyone to invest in their fund. Everyone is free to do as they please. However you should respect people that helped make Bitcoin what it is today, Charlie is one of these people.
He took one for all of us and I personally respect him for that. He's done his time and now wants to get back in the space with a new idea that has never been attempted before.
It's fine to be wary of new projects, better be safe than sorry. Make your own judgement before you invest any money in any new project.
But don't forget the contribution of people that came before you to this space and helped Bitcoin grow.
My 2 cents.
I dont know about the other guy but I dont respect any felon or support them.