See Jinnah was against this khilafat movement and he was against it for a reason. He said that it was unconstitutional, he also said that non-cooperation movement is not practical and it won't serve the purpose.
More or less it was a self-destructive movement adopted by Muslims of India. It was neither logical nor rational or practical. Of course we can't dump that all on Gandhi after all he wasn't the one who issued decrees (fatwas) to migrate to Afghanistan, or to resign from the very few hard earned jobs still kept by Muslims, or to stop sending their children to govt educational institutions or even the Muslim institutions accepting govt grants (including Aligarh)! We obviously had our very own 'thoughtful' leaders carving out these strategies
But the again he was there - leading. So Hindus were part of the leadership with that token presence and Muslims were bearing all costs alone.
And the timing at which he left the movement- not to say that chora chori was orchestrated by him as an excuse to quit the movement
but that was a terrible time to desert Muslims. It was right after 'Jail bharo tahreek' when Muslims leaders started offering voluntary arrests- all those leader were in jail. Howver, mindless they were but they were the leaders after all
And after Gandhi left there was no one outside to tell Muslims what's next. As a movement, it was a drastic failure! And after our own selves we have him to blame for.
It was like Muslims were bent upon destroying themselves and he was there making sure they do it to utmost.
And see this violence- was that a surprise after all. Isn't it what all agitations lead to? Couldn't he foresee it? Jinnah could! He told them then and there at Nagpur session.
This is what mobs do, they don't have faces or religions. When you ignite peoples' emotions no one controls them not even you. It's like Imran and Qadri taking thousand to constitutional avenue urging them to topple down the regime and then saying we don know who those people were, we don have anything to do with the attacks.
Back to the point there had been agitations and violence by Hindu mobs too, he never used it as an excuse to quit Congress. Then why Khilafat movement? His role in Khalafat movement was that of a pied piper not a leader.