He really didn't get it. Of course he didn't. Because to him it was perfectly natural to respond in such a way and not look at it objectively. Just because the way the two handled the dreams was different (gift vs curse, destiny vs destiny is a lie), he was still talking that, because he was the Doctor, he was going to do something. So she just sighed. "Just because your views on the matter are different and your goals, doesn't change the fact you're using who you are in the dreams as your reasoning behind it all."
Why was that so hard to understand?
"Never said it was you who thought I was weak. I was saying what his rant was about why I didn't 'understand' him." Because yes, the Doctor's ideals were ones that at least were good to live for. But it didn't change the way the conversation had been going despite the polar opposite sides of ideals. There was extremism on both sides of a spectrum that could sound the same, even if she wouldn't necessarily call Troy as being extremist in his views. But in his full on belief that he could do all the things the Doctor could now?
And he was proving why she hadn't said anything. Because he wanted to fix it, which meant he was putting himself in danger. And while something did need to be done, that didn't mean it had to be Troy. Not that Clara really knew what to be done either. So she just grabbed a pillow and hugged it to herself. Which at least was better than trying to hide her face beneath it.