Practically speaking, the mileage I can get out of learning Scottish Gaelic is marginal at best. It's a minority language, and I have few (self)-legitimate reasons, if any, to head off to the Scottish Highlands and Hebrides. Possibly, I will never get there in this life.
Despite that, and partly because of my genetic and cultural lineages, I spend a slightly inordinate amount of time on trying to acquire Scottish Gaelic as a language. It's far more culturally relevant than tartans and other rather late, suspicious, developments of 'highland' culture. I also find it about 300% more interesting and compelling than studying German, for which I at least have a motivating academic reason for learning (that leaves me fairly uninterested and easily motivated to let it slide).
Clearly, in the end, I am convinced it's worth it. Worth it to preserve one more speaker of a minority language, one more connection with an ancestral past, one more diaspora Scot who's prepared to invest time and effort into a worthwhile cultural endeavour, not some kitschy souvenirs.