I totally agree that gun hunting is cheaper. My wife reminds me of this every year...
That might have some effect on some hunters as to why they choose guns over bows but you have to agree that guns are easier. I have tried to talk a number of my friends and family into taking up bow hunting and they all tell me that they don't have the time and and the effort to put into it. Yet they will pick up their 30-06, shoot 5 shots at the range two days in advance, go sit out in a stand, and kill a deer on opening weekend. Seriously, how many of your friends do that. No practice, No scouting, No actual hard work.