Not dickish, just naive. If lawsuits were any sort of motivation, they'd hire an intern to send the twelve people their $50 in BCH by manually copying and pasting private keys into a BCH wallet app.

Edit to address your edit after my reply: no, there actually aren't any lawyers who believe they could "get 100 million dollars" in the situation you describe. The multistate bar exam covers torts and contract law (including equitable remedies), so there is no person licensed to practice law in Coinbase's jurisdiction who would calculate potential damages the way you have. In fact, if they did, they would likely be disbarred for incompetence.

Relevant legal terms to look up: compensatory damages, specific performance, contributory negligence, and good ol' burden of proof.

Finally, consider searching Coinbase's terms of service for "supported Digital Currency," "arbitration," and "waiver of class action."