Earlier quoted context omitted.
It's important to vote if only to make a statement that you care about the issue. Your silence is a vote of approval for the politicians to do whatever they want (of course they pretty much do already, but one should never implicitly vote for that).
Any vote is a vote signaling confidence and continued support of the democratic system. If you no longer believe that your system is democratic, then you should not legitimize it by playing along with it.
Who do you think is listening to your quiet signal? Who is supposed to care?