Overall yea definitely not a great idea to use a CC to buy crypto, but there's a few reasons I can think of that makes it worth it.

• Cash Rewards and you know you will be paying the balance come billingtime
• You're getting paid in a few days and will be able to pay off the balance come billing time, but you don't feel like taking money out of savings and btc hits a buy point

Other than that yea probably not a great idea, but banks playing the "too much volatility and risk for our customers" is BS...
Wouldn't be surprised if they try and pull something similar with debit cards and ACH transfers down the road.