There's another advantage for Orrick: Suppose a growing company were to come to Orrick for help with an M&A event, a VC financing, etc. Now suppose the company's initial corporate paperwork were a stew prepared by non-lawyers (or non-expert lawyers). That would make Orrick's job more difficult. So it's to Orrick's advantage to have the initial corporate paperwork be competent: even though Orrick doesn't necessarily get to bill for doing that initial paperwork, its later work is made easier.
It can also be advantageous in negotiations for Orrick's documents to have become de facto standards.
It can also be advantageous in negotiations for Orrick's documents to have become de facto standards.