Bull rush also doesn't require a to hit roll, nor do you actually need to be able to harm your opponent (for those times in which the creatures DR is relatively high and you're poorly armed) to be able to do it. Again, two especially nice things for a strong but lower level cohort.
But the way I see it, if it's useful for a cohort, why wouldn't it be useful for the main PC as well? I suppose it ultimately depends on what your PC-building goals are, but if you can think of a justification for saddling a cohort with the feat, it shouldn't be much of a stretch to justify picking it up for your own character. Anything that cohort could do with it, your PC could as well (and might be called upon to do so).