We're definitely in agreement with that. Abuse is a tough subject to broach, and requires a lot of tact to do it right, but if someone is well-meaning, I don't think the conversation itself should be shunned.

One time my sister's husband got frustrated while trying to load a bunch of stuff into his car, and ended up throwing something in his frustration. It wasn't at anyone or anything, but it was such a stark difference from how he normally acts that I felt the need to subtly take my sister aside and ask if he ever hit her. It was a bit awkward, but she knew that my heart was in the right place, so she assured me he wasn't abusive, and even told him what I had asked to show him how his action looked to a third party, which caused him to take me aside to apologize and thank me for looking out for my sister.

All that to say, it's good to care for your loved ones, and having mutual respect can let you poke your nose a bit deeper than usual so long as its for the right reasons. As a society we simply try to keep those situations from being necessary in the first place, which is why we tend to be uncomfortable with relationships that are at a higher risk of being abusive.