There are lots of articles on how to use Sybase Open Client bulk interface saying that it will only work if the connection used is "bulk enabled". Which begs the question why wouldn't I always create connections that are bulk enabled, even if I may not use them for bulk operations. I can't find anything that talks about this.
Best How To :
Bulk operations do minimal to no logging in the database. This means that in case of a server failure, transactions could be lost, and there would be fewer recovery options available.
So the default is to make things as recoverable as possible with being bulk options being disabled, and letting the developer and dba decide whether to enable bulk enabled connections, and live with the possible impact on operations.