Developers and Making Changes

I have only done a few MMOs but I have noticed a trend that when developers gather the feedback from the community, they almost never implement anything suggested exactly the way the community posts, even if it may the the easiest/best way to improve or fix something. They will most likely come up with some backhanded way to fix the problem that either is not very effective or can create other problems.

One example I think of is the buff to Power Word: Shield. This spell needed to be scaled for a long time. Instead of just scaling it as the community suggested, they decided to get cute and scale it according to +healing items. So instead all priests being able to to benefit, Holy priests will get the primary benefit.

Why is this? Do they think it's a sign of weakness to accept feedback from the community and implement it in the best fashion possible?