Neither trade secret nor trademark nor service marks protect my creative work; only copyright. But my copyright is my business just as the source code is the foundation of Joel's business. So what Joel thinks is good for my business is surely acceptable for his own.
If anti-copyright folks are as concerned as they claim to be about adding value back into society - and as quickly as possible at that - it makes overwhelming sense that valuable services such as software should be scrutinized first, before mere entertainment. We should obviously be talking about limiting a term on trade secrets - not just copyright - people will still have trademarks and service marks to defend their reputation and authenticity.