Well in my 22 years experience (as a girl through to adult leader, in 3 different locations), I've never known anyone get thrown out for anything other than being too old for the section (when they are pointed at the next one).
I have known and loved working with girls from almost every nationality I can think of, girls with EAL needs and different religions.
I've supported a 15 year old through unplanned pregnancy ( without feeling the need to kick her out!)
I've worked with girls who swear, occasionally at adults, girls who refuse to wear uniform, girls who refuse to camp, girls who bring white towels to camp (hahaha), girls who smoke, girls who would prefer to nip off to the next field to snog scouts that might have been me age 15 . I refused as a teenager to do the hardest badges, mainly because I couldn't be arsed. Noone kicked me out.
And yet if I had a £ for everyone I've heard claim they've been kicked out, I'd be rich. I wish I knew where these kicky out units were based. I genuinely can't imagine kicking out a girl for anything that wasn't actual criminal behaviour (and even then I'd try and work with her first).