Just my opinion but I think the conspiracy theories are not realistic. Coinbase is essentially a startup that is dealing with monstrous traffic. They are still scaling their infrastructure and when the price starts moving quickly everyone logs in to either get in on the action or take a look. This cranks the traffic up and the servers cant handle it. I am not excusing their behavior as they need to be able to handle…
Coinbase goes through this charade every time this happens with a major digital currency. It wasn't a legitimate excuse the first time, and it's not an excuse the 7th time. Scaling is a solved problem. You have AWS, Google Cloud, and MS Azure to choose from with financial institution/HIPAA-level offerings.
By most engineers in the field it is a difficult problem with ongoing work.