Call me cynical, but if I heard about which players had done this, I'd wonder who they'd done it for. If you genuinely do it out of care and consideration for other people, then does it matter that other people (ie. us) should find out? On the other hand, if someone expresses their condolences publicly, then are they doing it genuinely or just to look like the good guy? In which case, do they really care or is it to preserve their image?
I know where you're coming from, wanting to know who cares, but quite frankly, anyone who is public with their expressions may not have done it for the sake of the people who have suffered a loss.
Having said that, I'd like to think that some players will pass on messages to the family, just not for us to know about.