Earlier quoted context omitted.
You can argue that a lot of people (Democrats included) didn't want to vote for Clinton either . By that argument you're justifying both candidates' character flaws by saying "Well, you know the other person is just as bad as my choice, so that makes it OK".
> justifying both candidates' character flaws > so that makes it OK How? This is your interpretation. If you have a choice of two, you must pick one. You have to weight up the options. choosing one doesn't automatically mean endorsing it as the post possible choice, but just the better of the given options.
If done properly then abstention is a perfectly valid alternative to not voting at all, because your vote means it's more difficult for the parties to obtain a majority. If you don't vote then (ideally) you have no effect on the numbers. Whether this is how the US system works, I don't know, hence the ideally.