Club acts used to to sabotage each other if the opportunity arose. Either by pulling a lead or, more commonly, by de-tuning your guitar after you'd sound checked! There was no humour in it, just malice and proffessional jealousy. I didn't understand it then and I don't understand it now! I like to think I'm encouraging to other musicians and have never refused to answer a question or show someone a chord or lick if asked. I've always felt a common bond with other guitarists.