Unfortunately, there is an even worse alternative for developers of classless bulk devices: your device driver can end up not working anymore.

This actually happened last year: a major microcontroller manufacturer who supplied a bulk device driver for classless bulk devices ran into big problems with Windows Vista. They were unable to provide a device driver that would work under Vista for 9 long months.  (That must have been some expensive months for companies which had developed and released some of those classless bulk devices...)