I've never heard anyone claim that casinos set their maximums to prevent martingale. Only that martingale is prevented by maximum bets (i.e., all keyboards have keys, but not all keys are part of keyboards).
yes they do set that to prevent martingale,as the player might have a chance of losing lower than 1 in 100 gazillion times.
atleast all the online shit has it ,PD has 20 coins limit JD has it too.
It is not. But if you believe the max profit is the only thing stopping you from winning, you can play on JD which has a min bet of 0.00000001 clam and a max profit of over 200000 clam (=1100 btc).