I think it's quite a bit less complicated than that. Most of the talent are actually good at their jobs and very hardworking. Pimp included.
Obviously something external like accents and personality traits are not considered by these companies as they simply look for people that are good at their job. That's almost the sole factor, as long as they don't make the employer look bad.
Just look at the LoL scene or other esports segments. They have a lot more casters and/or analysts that can barely speak English or have weird quirks that would be considered unprofessional in that regard.
I think the best example in this scenario is Thorin. He's very controversial and have a side of him that can make his employers look bad, which is why some don't want to hire him.. but he's still a magnet for viewership. It's for the company to decide.
As for cursing, that is only an issue in regards to American sponsors. That's also why you see ESL not really caring about it, but will try to avoid it as much as possible.
SPUNJ is the best there is at his particular job. That's why he's given a very long leash in terms of all of these things. Even in terms of criticising Valve at their own event.
We've actually seen quite a change in the talentpool over the last year, which is both because of controversial incidents and casters simplybeing worked too hard compared to their pay and their free time.
Also look up on how Bardolph treats his colleagues.