I'm sure the Sharks players aren't trying to lose, but a DGAF mentality can build quickly though. You start losing and know your roster is sub-par and know you are going to be bad, it affects players. You aren't going to kill yourself to block a shot, you might give it 90% in a board battle, you might stop 1 stride short when back-checking, etc.. etc. It's not an indictment of the players, or coaches, it's human nature, especially for guys in their late 20s or early 30s.
It's easy for us to say "They are earning a salary, so suck it up", but being on a losing team with no chance for the playoffs from day 1 will wear them down.