If you employ someone in a low - mid level position in an office in HK they are certainly going to have to be dealing with people on a daily basis who can only speak canto-pop or prefer to speak canto-pop; so an employer will, certainly want a canto-pop speaker. Cos otherwise you will be lumbered with a serf that will wander into your office multiple times saying that there has been a misunderstanding or most likely as an employer you'll find out only after the SNAFU that communication has caused great wailing and gnashing of teeth.
And given it is easy to get low - mid level staff with canto-pop; that's what y' employ.