That doesn't have anything to do with liking conservative ideas or not. To the point, how dare conservatives not stand up for their ideals and say no to Trump? Or do his supporters actually believe what he is saying (this week)?
I'm somewhere bouncing back and forth between conservative and libertarian at any given time, but I'll attempt an answer (an answer that assumes that a person is conservative first, not Republican first). I think many conservatives are saying no to Trump, some parting ways with the Republican party in the process, but at the same time trying to figure out what it looks like to stand up for their ideals in this cycle.
If you're pragmatic, who do you vote for? Is it better to pick the devil you know (Clinton)? She's some mixture of conservative (in the aspects of conservative that serve to protect those already in power) and progressive. On the other hand, Trump is unpredictable. While I don't expect any candidate to be telling the truth, I typically expect their campaign stances to correlate somewhat with their eventual actions in office. With Trump, you know that some of his actions will connect to what he says in his campaign only because he's said so many things all over the place, including contradicting himself, that it'd be impossible to avoid doing at least something he promised. So do you march to your eventual doom with Clinton, or play Russian roulette with Trump? Certainly the libertarian candidate isn't a pragmatic choice, as he's not going to win; he's a bad choice even if his platform did align with conservatives in some way. So you're left with game theory and trying to predict the actions of a group of people you don't trust except in that you trust they'll make many of the wrong choices if called upon.
If you're idealistic, what do you do? All three significant options are maybe even more terrible. You can't even rationalize that you were just voting against so-and-so if you're idealistic. Is saving an hour of your time (by not voting) idealistic? Maybe that's the only rational choice. Or you could try to start a fourth candidate, but few people are willing to throw themselves at such a thankless and impossible task just so that they have someone worth voting for.
If you meant to ask this of Republicans, then I'm figuring the faithful Republican looks at all the different garbage heaps running for office and says, 'well, I know I don't want the other team to win, so my hands are tied.'
For my part, nothing Trump says could make me vote for him, because what he says is about as relevant as his bowel movements when it comes to predicting his future plans. All I have to work with are his odious past actions against private property rights and his (sort-of) alliance with the maybe-less-bad party. It's possible Clinton could convince me to vote for him, but I'm doubtful of that happening.