Well, it's not unreasonable for the Scottish National Party to want independence for Scotland, is it? You may as well ask the Tory Party to stop running with policies that help the rich get richer.
England has given them another excuse to have another go by its decision to go with Brexit the way it has. This and the NI situation, as I have said since before June 2016 and many times since, was always a likely consequence. The hard-line Brexit approach has only made it more likely. Anyone draping themselves in the Union Flag and declaring for Brexit is leaving themselves open to ridicule.