The banks like this sort of additional phase to online card transactions. This phase is very effective at combatting fraud.
Merchants who don't support it may find that their sites are deemed at 'high-risk' of carrying fraudulent transactions.
Phishers who have illicitly acquired someone's card details often try a small transaction on non-merchandise sites like charities, to check that the card works. Faking a race entry might serve the same purpose.
So it might not be all down to RW. It's probably pressure from the bank's anti-fraud team. Without the additional verification, you might find the transaction gets blocked by the bank's fraud-screening program.