Not everyone buying coins are numismatists. They include impulse buyers, investors, misguided investors, souvenir buyers, present purchasers and one-off buyers.
The offerings from the Royal Mint are rarely aimed at numismatists these days, but at the other groups. Their mission is to simply to make money (banknotes rather than well-designed coins).
It's easier for numismatists to just ignore the souvenir coin market.