First of all, I would disagree in your estimation of how many players are actually hackers. Only a very small number of players hack, and usually are people who just drop in to hack for a few minutes till they are banned. Thats 90% of the HHG hackers. A few serial hackers are banned soon enough as well and removed from HHG.
That being said, the main reason players report/tell online staff about hackers is that it ruins their gameplay and they want to play normally. To make it reward based would cause numerous problems. First, it would be very hard to implement. Players would be begging for their rewards and all clamoring to make reports, valid or not. Secondly, this would result in a lot of spam reports and just nooby players reporting for hacks or whatever. Thirdly, if only hacker reports gave rewards, then players would often not like to report other rule breakers, like people who spam or swear, as those reports dont give a reward. As a result, we get less of what we do want and more of what we don't.
And if we do add all offenses to the "rewarded" list, then it gets even more spammy!!
All said and done, I think the problem of hackers is being dealt with very well. People report hackers consistently already and staff are able to get on and deal with them. But the problems created by this reward system and the difficulty implementing it would be too much I think.
Finally, as far as "us never accepting ideas", perhaps its not the mean old staff not liking ideas but the players not having valid/workable suggestions. So, don't please don't cry about not having ideas accepted. The suggestions page is for community input, and its good to get ideas out there... but they are just suggestions and ideas for us to bear in mind and maybe implement, and maybe avoid. It just depends.