I suspect that a major factor in the keep-it-under-your-hat approach to publicising folk activites (other than festivals) in England has been the the Public Entertainment Licensing situation.

And also the absence of any equivalent to the two-in-a-bar exemption which pubs have had, for any premises other than pubs, has greatly restricted the places music can happen. Some of the most important folk clubs back in the 60s took place in coffee bars and so forth.