I agree, however I feel that there's more to what these people are trying to do when they say something like "there's worse situations you could be in". I believe that a statement like that works to reinforce positivity. And psychologically, that has its benefits, wouldn't you agree?
Someone who is depressed cannot possibly be hurt by hints of positivity. While they don't provide a cure to the main problem, they may help to discover one.

Just my two cents.:hippy: