Welcome to Gaia! ::

From what I can tell there are two factors that feed these problems.
The first is the rampant publication of misinformation. People read them and feel they have done their research and because they have read x number of sources that say xyz they feel it has to be true. It can be hard for them to fathom that those source materials all have it wrong. So they stick to their convictions because they don't feel they have been lazy and they don't feel that that number of sources could be incorrect.
The second is the persecution complex or personality replacement syndrome. Some people are just immature. They feel the need to gain attention or sympathy by joining a group they perceive to be persecuted so they can be special and different. Others are not sure who they themselves are so they try to use being a witch or being pagan as an identity or to make themselves seem more interesting to others.

i have to say, when i was first, i dont know... 'converted' to paganism i had a group at college. i couldnt fathom being solitary, it wasnt my style at all. but for similar issues, i have ended up cutting myself off from everyone in that group (save my girlfriend) and although it is not ideal, i have embraced solitary practice.

it simplifies things, at the very least