Original sentence: The brothers are often criticized for producing poor quality slap-stick comedy.Their supporters however claim this is due to many people failing to understand the more subtle aspects to their humour and their effervescent and likeable personalities, which give some of their shows the potential for immense comedy and entertainment
Edited sentence: The brothers are often criticized for producing poor quality slap-stick comedy; however, this is because many people fail to understand the more subtle aspects to their humour and their effervescent and likeable personalities, which give some of their shows the potential for immense comedy and entertainment