Can vouch that sales team is an immense advocate for customer and frequently pain in the kiester for people who are trying to do stuff.

Mind you, you absolutely Can get into a negative loop - needy customer with unrealistic expectations who over pressures the sales person, who then over pressures the pm, who then over pressures the team and you end up with unfeasible expectations and conittments. But sanity needs to prevail everywhere, it cannot be focused on the "good kind of salesperson"

(I will never ever ever be a sales person; and I share most people's frustrations, but I've also seen what the good ones do for the customer and teams so am slowly starting to understand both the value and necessity :-/)