Xanadu, you appear to have misunderstood Mark. What Mark has written about has absolutely nothing to do with "bets not honoured" or with "funds not being safe" in betting exchanges. All bets in a betting exchange are made with money that is already there. Mark posted about banks apparently stopping people from using their credit cards to deposit money into a betting exchange.
This has nothing to do with "bets not honoured" or with "funds not being safe" in betting exchanges.