According to Wikipedia, Max's father was killed in an underground pit explosion a month before Max was born, and Max worked in a colliery himself before he became a star, so I'd suggest that his emotion in singing about Welsh mining culture is completely genuine.

Max came out of folk clubs to become a more mainstream folk-comedy star, at around the same time as Jasper Carrott, Billy Connolly, Mike Harding and Richard Digance did in different parts of the country.

I'd recommend 'Duw It's Hard' to anyone who wants to hear one of Max's more 'poignant' songs - http://www.youtube.com/watch?v=7itxshX1i4o