getting safely to the gate is a MAJOR consideration in Cat III operations.
And how about getting FROM the gate TO the runway during low visibility conditions? I'd say it's just as much of a challenge. If an operator is approved for 600 RVR departures, it's pretty likely that they'll encounter visibilities of LESS than that during the TAXI phase. Or is that part of the takeoff?
But I agree in spirit with what you're implying intruder. In fact low RVR isn't necessary to present effectively poor visibility types of challenges to taxiing safely to or from your parking position. Especially at night. Or while it's raining/snowing. The way some of the lighting on the airport can glare off of wet/snowy/icy surfaces and windshields might make you want to whip out the low vis taxi chart and request a new taxi route!
In any event the specific criteria defining different phases of flight vary somewhat according to who defines them and for what purpose. Accident statistical analysis, certain aviation regulations and operator SOPs all differentiate between classification of events or requirements according to "phase of flight". A separate taxonomy for each purpose and usage it seems. In flying as in normal life, I find the inconsistencies in the use of terminology to be the single biggest source of misunderstanding among my peers. As such, this little discussion certainly does no harm even though it can easily be seen as having devolved into esoteric pedantry.
westhawk