I haven't watched the british version of these shows - but I did see one season of american idol (way back in the first year of grad school... when I'd just leave the tv on for noise)...

And given from what I remember of that season, I'd say in general... the judges did treat Susan relatively nicely at the beginning... They obviously thought that they were humoring her... But from an american idol point of view, Simon was actually being fairly nice.

I think anyone who has seen the shows pretty much expects to be ripped to shreds by Simon.

I'm not saying that excuses any of it, but that's the norm on these shows.