We may call the two styles of Vajrayana Buddhism the institutional and the shamanic styles. While the institutional form is dependent on the shamanic, the institutional form does not trust the shamanic approach and is not comfortable with it.
The institutional approach has beliefs and practices that have been analyzed and vetted, carried down and performed by groups over the centuries. Any dangers or problems will have been encountered and dealt with. This approach is safe following the one shamanic or inspired figure allowed by the tradition, the founder. Everyone else is suspicious unless they are formally accepted by the leaders of the tradition or lineage. The process of gradual acceptance allows new ideas to enter.
The individualistic approach which we call shamanic does not follow a set formula. The person is called to practice but often no teacher is available. So practice is erratic without group sanction when trying to learn about the path and its goals.
The calling of the institutional novice is to join a group. The calling of the shaman is to have an experience. The first is conformist. The second is unpredictable.
The monastery or lineage is a group, and all travel together towards enlightenment. But it is slow like a wagon train crossing the plains. It is like travel in a group where the old are tired, and the children want to go to the bathroom or stop and play.
The individual path is not delayed by the group - all delays are the person's own responsibility. So are the strategies of learning - whether directly from a Yidam or deity, indirectly through spiritual dreaming, or yet more indirectly through the interpretation of sacred texts.
Novices in institutions envy direct learning and often dislike those who claim it. The stated criticism is lack of humility. The deeper problem is resentment. The novice will say that people outside institutions do not deserve such gifts. Only the institutional practitioners do. They have done more, worked harder, and often had limited success. What right do others have to claim visions? If anyone deserves them, the institutional people do. Those who claim direct experience must be lying.
This problem has hobbled the development of Buddhism. Between rival orders fighting for dominance, rejection of visions among their own members, and suspicion of non-members, valuable sadhanas have been lost and the visionaries rejected. Many Buddhist orders have retreated to philosophy with logic as the gatekeeper rather than the Yidam.
Such an approach gets narrower and narrower with only commentaries on a single experience accepted and vision shrunken to a spot on the wall. The lack of encounter with Yidams and deities means people must stay longer, work harder for the institution, and bring in more money. The narrowing of the tradition snowballs.
Thus, Yidams have often chosen to work with individuals rather than Buddhist groups and people within the groups whose visions are likely to be ignored. The group and individualistic styles clash, and they reject each other. Only lamas of high status are allowed to add doctrine.
To the visionaries outside of institutional Buddhism, do not feel that it is necessary to join Buddhist groups. Instead, it is often better to do the work you have been called to do on your own.