Fatal flaw in the udev paradigm?

I have run into an issue which seems to call into question the udev
paradigm for USB devices. In my case it has ramifications in
ModemManager and gpsd packages, but I see it as a fundamental problem
with udev which is in all current versions of Fedora.

My USB GPS is a BU-353 which uses a pl2303 USB-Serial Controller
(idVendor=067b, idProduct=2303). However, bugzilla report 878737
indicates this same interface chip is used on other devices such as
RS232-USB adapters. 

If the device is a GPS you do not want ModemManager run on it
(bugzilla 1023234) but you do want gpsctl to tell gpsd about it when
it is plugged in. If it is a RS232 adapter the opposite is true
(bugzilla 878737). Note that it is reported that the DU-353 can be
bricked if the wrong thing is written to it. 

After looking at the lsusb -v output for my BU-353 and the output for
RS232 devices reported on the net, I do not see any way to distinguish
between the two different types of devices that udev could use to tell
them apart.

Unless I am missing something this seems like a fatal flaw in the udev
paradigm.

Regards
Roy Rankin