That's a really broad question with no specifics but I'll give a shot at it.

Me personally, there's plenty that is too valuable that I wouldn't sell it. But there's nothing too valuable that I wouldn't it hold to the same standard as everything else. In my opinion, if you make an excuse for one thing, excuses will be more likely to come up in the future for whatever reason. I do agree with the above point about the phrase being subjective and I also agree about it being used as an excuse very often.