Commercial Fishermen are already being paid "bonuses" with the market price they currently receive for their catch that's propped up by subsidies from KDFWR and other funding sources. If it weren't for all the subsidies/bonuses being paid out, the market price on it's own would be so low that the guys you saw wouldn't even be out there. The market for Asian Carp pretty well doesn't exist, that's why the price without any subsidies is so low, and also why commercial fishermen are still struggling with finding buyers to take their catch. The Kentucky Fish Center/Fish Market was closed for a while at the end of last year, which pretty well stopped all Asian Carp commercial fishing on the lake up until recently.
As for the research, the money for that is from the government with a stipulation that it must be spent solely on research to try and figure out how to effectively remove Asian Carp, not just from Kentucky Lake and Lake Barkley but from waters all over the United States. The results of the research will have a national impact, not just local. Plus you can't just up and decide to take research money and give it to the commercial fishermen, that's not how it works.
Current prices for Asian Carp:
Kentucky Fish Center | KDFWR