the bass and kicks take up a lot more of the high end than a lot of people think. obviously it depends on your track and what you are trying to do, but take a kick for example. the 'click' of a kick comes more from the 2-5kHz range than the low end, and this is one of the most important areas for making a kick punchy. it is perfectly acceptable to have stereo effects in that area, although more so for bass than for kicks.
i tend to keep everything mono below around 150-200Hz (depending on the track), but anything above that will be stereo to some extent.
i tend to keep everything mono below around 150-200Hz (depending on the track), but anything above that will be stereo to some extent.