Riiiight. Because no lawyers have ever smelled a new ambulance to chase kicking off dozens of harassment suits when new precedents are handed down. Oracle has already threatened OSS databases, Samba was once threatened by Microsoft aggressively, and whose to say WINE and other OSS API reimplementations won't be under legal threat the way Unix reimplementations were.

Any precedent that establishes clean-room API reimplementations are subject to copyright infringement is bad for everyone.

You're willing to risk throwing out the baby with the bathwater.