It's 100% not a choice for them.
Technically, anyone buying or selling $1000 or more daily requires the service to collect customer information, and retain the customer and transaction information for 5 years. Over $3,000? Then you also have to verify the customer information. Other regulation that likely applies to Coinbase actually requires 7 year data retention, so they may likely be cutting it short by 2 years. They were pretty blatantly not following the BSA rules for quite some time after FinCEN gave guidance on money transmission and bitcoin and only recently got in line. That makes them outlaws and popular here, right?
If you exchange fiat for bitcoin in the USA, you need to be doing the above or you can be shut down and/or go to jail. You should also know that other ways to exchange are not exempt from this law, it's just much harder to enforce. If your service is OnlineTM and not dark web, forget it, you are going to be following these rules or you are out of business.
So yeah, while I love a good pitchforking, this particular one really isn't on them. The BSA was drafted in the 70s before people used computers commonly. It's the root cause of identity theft because it massively increases the attack surface for identity thieves who steal information from companies who have to store personal information in 5-10 different places and with different vendors. It's an anachronistic and dangerous act that needs to be completely tossed and redone in a way that scales with technology over time and doesn't create another outdated regulation disaster in 20 years.
I'm really not a fan of static regulation that doesn't get updated for decades and directly affects rapidly evolving technology. It's hard for me to imagine a more backwards way to manage this type of industry, short of completely nationalizing the financial system.