Misdemeanors have a maximum penalty of $1,000, and 90 days in jail. GM's are $5,000 and up to a year. To change the classification of the crime would generally require legislation. Things get stickier from there.

The income part of the equation would be offset by the cost of prosecuting them, most likely resulting in LESS money. Most poachers are not well off with loads of extra cash, so then you get to the problem of the collection of their fines. They might be able to go bankrupt and have those fines forgiven by the court.