There is nothing wrong with just liking music and wanting to perform it - but likewise music is just as valid a subject to study as Art, Dance, history or whatever and why should folk music itself not be worthy of study? The curriculum for instance at Newcastle is not just about performance (though you do get one to one tuition from the likes of Kathryn Tickell) as it delves into the history of folk music throughout the world with modules perahps on the Renaissance or Indian folk music or music and cultural theory modules or compostional techniques etc. If you were interested in music then what is wrong with wanting to study it? Though obviously your perfromance skills are are a big part of it there are employment and work opportunities from getting a degree other than performance too!