To me, and I'm a commercial producer, I don't really worry about a cow's udder, unless, I have to help the calf with it (or it is literally so bad it is dragging on the ground). Not to say I don't pay attention to them, but that I won't cull a cow just because she doesn't have a 'Perfect' udder. I won't keep a heifer off of her if her udder is bad enough, though. I'd keep a calf off the cow of inyati's in a heart beat, but then again, I'm not a seedstock producer, and I'm not going to affect anyone's bottom line but my own. We don't have a lot of problems with udders, and as far as mastitis goes, we've had more problems with 'good' uddered cows than with poor ones... Now having said that, we have a pasture that we run a terminal bull in, and that is where all the 'bad' cows go. Anything with a bad enough udder, bad feet (I worry more about them than udders), poor temperaments (although those don't usually stick around long enough to get bred a second time), and poorer producing cows that can use that little extra boost of hybrid vigour.
Just remember, in the pursuit of perfection, there is going to be a lot of non-perfect results.....If we kept only the perfect ones, our herds would be pretty tiny.... It's just a matter of deciding how perfect we need them to be.