British accents in SA radio ads

Standard Corporate and Merchant Bank, Old Mutual Asset Managers (both of which use the same guy), Discovery...why do they all use a Brit as their voiceover artist? The voices are never obviously English, but anyone with an ear for accents can tell that they are not South African.

Presumably a British accent sounds suitably upmarket and intelligent. Which in itself is a bit of an insult to South Africans...I think.