I do not understand why the chat on Meta SO cannot be open to new users with less than the minimum amount of points. Sometimes it is very hard to quite understand how to pose a question, and I think the guidance of older users on the chat could be used to help the entire community. My question is then why doesn't SE open the chat? What is the logic behind this?
No. The guidance of established users in chat only helps the person who is in chat at that very moment, and is then lost within the chat transcript. The community doesn't benefit from that.
The guidance of established users through questions and answers on Meta Stack Overflow, however, has a much bigger chance of also helping others, not only the person asking.
It's the same reason that the other chat sites have a minimum reputation requirement: To prevent new users from using the chat as a replacement for the Q&A site.