I have absolutely no problem with voting your conscience where it doesn't actually "matter" (i.e. non-swing states) or on the local level, on the contrary, I very very much encourage it.
I do, however, have a problem with those where it actually DID matter and decided the election, because it comes down to either ignorance or indifference.
Sometimes I have to put my own pride after what's best for the community, society, at large and go with the compromise option.
But then again, I'm European... your guys' two-party system and Electoral College is MAJORLY flawed anyways.
However, there actually are statistics that show that the Republican candidate (i.e. Trump) did receive the same amount of votes than Republican candidates in the past, whereas the Democrat candiate lost votes to either third-party or non-voters. So yes, they did make all the difference.
And I just personally think that sometimes it's necessary to hold your nose for a little bit as to not loose the long haul. There are times for making a stance and times where one should just swallow one's own pride.
I myself have voted not for "my" party/candidate but for the best next thing in the past just to not waste my vote, but did vote my conscience when I knew they'd actually have a chance and my vote actually would matter.
Edit:
I keep seeing (Bernie) folks equate any of the other establishment/corporate DNC candidates with Trump. And this is just utter BS and the very same propaganda the GOP is using, just from the left. I'm seriously no fan of most if not any of them, but basically going all "same same but different but still same" is not only BS but just plain dangerous and that people don't even recognize that (or don't care) speak heaps about their positions of privilege.