I think this is misleading. The people who were encouraging violence were not leaders of the student movement. From what I understand there were a number of different groups with different goals in the square, but the majority were young people who wanted an end to market reforms that were causing strife and a return to a more communist economy. My understanding is that there were also a substantial number of people who were advocating for more relaxed, permissive social norms and who believed that the social conservativism around things like public affection, dating, casual relationships, dress, and music were not in keeping with communist values.

The group of CIA backed students who attempted to initiate a violent confrontation was very small, and from what I understand they basically bullied their way to the PA equipment and took it over. They were not popular and many people were confused by them, but apparently the students were unsure what to do with them. At any rate they had little if any influence and their attempt to start a color revolution failed miserably. Shortly after they tucked tail and fled to the USA as part of a CIA operation.