To claim that voters are noticed by politicians or even respected by them is not very realistic. It is not at all hard to find evidence that voters and non voters are both disregarded by politicians.
Voting has no practical effect on defending one's interests. Influencing large number of voters may have that effect, but voting does not. Not voting, on the other hand, pays out immediately. He who decides not to vote immediately earns some free time. I don't mean the time not spent on voting, but the time not spent on watching liars debate, reading lies on newspapers and getting informed of all the lies each liar team tells.
There is more to it. Not voting may indeed hurt the so called legitimacy of a government.
Lula in Brazil was very proud of the millions of votes he got. So did all the other presidents. Usually, however, most of those votes were simply votes against the other guy. No one remember that after the election.

Think for a moment. In two years people will not say that Hillary won the election because people didn't want Trump. They'll simply say she won.

Voting is an act of submission. An act of submission has an external effect of legitimizing tyranny, but a more important internal effect of submitting.
I know it is hard to admit it because most of us have voted before and are not willing to conceive that the very act we thought could help get us free was a surrender to the slave owners. Unfortunately, it was.

Have you never heard that people should learn to vote? That the country can never prosper unless people stop voting on corrupt politicians? These ideas clearly state that those who voted on thieves are partially responsible for the theft. They state that voters legitimized anything, I repeat, anything that the politicians did afterwards. Also, one should note that people usually accept that. I once asked on a forum why the US dropped the second nuclear bomb. I was bombarded with comments that considered that a stupid question, legitimizing the act of murdering thousands of innocent people. Those people were simply identifying the act of a past government as their own.

It may be that those who are silent won't be heard. It is also true that those who ask their master for freedom have surrendered it to them.