I think you can mock people and insult them if they've genuinely been stupid, for the sake of a TV show, but belittling someone's real achievements or suggesting their approach to work is flat-out bad when maybe it's just not appropriate for the task is less acceptable. "Ruth, you talk too much" I think bordered on being a personal judgement rather than a professional one. Also Ruth being set up as 'talky' happened very suddenly didn't it, for someone who'd been the voice of reason the last few weeks.
I also didn't like when Scott defended Selina and Claude mocked that. I think Selina is an odious little woman, but she was only, as she said, triple-checking the price with Scott before she made her sale. Selina said so, Scott said so, and the video evidence said so. Claude came in saying something like "Scott, you're being too kind to her, you really did that sale didn't you" which I thought was very patronising to both Scott and Selina, not to mention being a falsehood, or at least a misrepresentation of what happened.
I think they're trying too hard to set Selina (for example) up as a villain. Her own soundbites and attitude do that, you don't have to deliberately and vocally try and undermine everything she does just to suggest to viewers really heavy-handedly that she's no good.