One important part of human interaction is that you can trust someone and that you yourself is trustworthy.
This is even more true when you do project work. In fact that is the contract between the project management and developers - and between developers themselves.
I don't know how often I've put in an effort to lift my part of the work, only to find that others really couldn't care less about the deadline, the users or the customers that really really need this project to finish.
My usual response is to try to help, lifting some of the work that others should have done. Sometimes I get so tired of this that I want out.
I think the problem has been escalating lately. Or is it just me being more sensitive?