Because JMM didn't move up in weight while throwing 1200 punches vs. guys twice his size and knocking legit champions out in two rounds. Take the tests.
JMM has only introduced this Heredia guy recently. He wasn’t around when Floyd fought him. And the other reason why Floyd never asked OSTDs from JMM, is because there was nothing for Floyd to save face for, at the time. He began to worry about Pac and launch his baseless accusations approximately 2 months after fighting JMM. It was then that he was forced to demand OSTD from all of his future opponents to make his farce seem acceptable.