Um, yeah, no. Not at all.
Longevity is VERY important. High milk production isn’t necessarily inherited from the dam/can be positively negatively affected by the sire. Feet, omg, feet (but we’re not getting into that here or the AQHA folks might have a meltdown )
Then we have stuff like udder shape and size, and teat placement - all somewhat related to longevity, overall health, value, and potential to be used in a modern robot barn.
That’s just a very basic start. To be honest, most of it went over my head because it’s flippin’ complicated (and not my cowz, under my care, but not mine).
It was a well known if somewhat rare issue that had ZERO impact on the stallion or stallion owner unless they ever got another mare in to breed with similar blood type (or whatever the hell it was) in which case they could say, “Hey, yeah, actually we had a blood test done last year for another mare like yours and we’re good to go! Here’s a copy of the results.” or “I’m sorry, but we’ve already had his blood tested and he’s not a good match for your mare. Sorry.”
That is literally how it went. It wasn’t looking for a fault in the stallion. It wasn’t a fault, it was a compatibility thing. You remember that House (or Grey’s? or something lol) where it was discovered that a woman was allergic to her partner’s semen? Something like that except it would be the foal that was affected, not the mare.
I do not understand why people are so frightened of knowing things about their horses. Being frightened of something so simple sure sheds some light on how things might go as more is understood about heritable traits in horses