Great post Vladi!
And, i think you hit the nail right on the head with this one. When I see high rollers at MGS, they are depositing $5-10k / day at times. That would be counter-productive at Rival Casinos because they could not ever catch up with that big win.
For example, I had one player that would spend $10-15k in a week. Might win $30k and cashout. Then would proceed to redeposit that amount over the next day or 2. It was constand deposit/withdrawal. With Rival - that's just not possible. The withdrawal limits make it that way.
Here are some examples:
Rockbet Group:
Vegas Days: The casino reserves the right to limit withdraws to $2000 per day and $4000 per week.
Rockbet:The casino reserves the right to limit withdraws to $2000 per day and $4000 per week.
LionSlots Affiliates:
Lion Slots: A player is permitted to withdraw a maximum of $2500 USD of their winnings per 7 day period.
Pantasia Group:
Pantasia: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
Mayan Fortune: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
400 Affiliates:
Cocoa Casino: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period, $4000 USD per week and a maximum of $16000 USD per month.
ThisisVegas: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period and $4000 per week.
Paradise8: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
Davinci's Gold: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
Superiorshare:
Superior: A player is permitted to withdraw a maximum of $4000 USD of their winnings per 7 day period.
Slotocash Affiliates:
Slotocash: All payout's over $5,000 will be paid out via installments not exceeding $4,000 per week or as per mutual agreement with his/her personal account manager.
Regal Affiliates:
Vegas Regal: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
Slots of Fortune Affiliates:
Slots of Fortune: Players can withdraw up to $2000 per day and up to $4000 per week. Higher limits may apply for regular and VIP customers.
Simon Says Affiliates:
Simon Says: A player is permitted to withdraw a maximum of $2000 USD of their winnings per 24 hour period.
First Gaming Partners:
Slots Power: A player is permitted to withdraw a maximum of $2000 USD of his/her winnings per 24 hour period.
Vanguard Casino: A player is permitted to withdraw a maximum of $2,000 USD of his/her winnings per 24 hour period up to $4,000 per week. A fee may be charged to the player to cover payments made by check.
Ruby Royal Affiliates:
Ruby Royal: A maximum withdrawal limit of 2,000.00 (USD, EUR, GBP) and 20,000 (RANDS) per 24 hour period and 4,000.00 (USD, EUR, GBP) and R40,000 (RANDS) per week will apply to all players.
There are, of course, more Rival's than that, but that is the gist of it

If this is not accurate, then the casino needs to update their terms of use.