I employed one 6 months ago and literally just scheduled an interview with another this morning for later in the week. Fun times...
UK Work Permits are trivial to get for tech workers from anywhere in the world.
Sure, they can definitely come in with another visa but that requires a fair bit more work compared to a 'local' hire which is an added cost. Then once they get here (if the article is true) they don't have any right to remain in the country for an extended period of time which makes attracting them over/keeping them here even more difficult.