Glue ball
See what you are saying and departure minima have nothing to do with landing minima, but you say
The only criterea when departing from an airport that is below landing minimums is to include a "Departure Alternate" for planning purposes.
which is not strictly true as with a minimum departure vis of 125m RVR and a CAT IIIb approach minima of 75m the airfield landing minima could be less than the departure minima, thus the criterion for the departure alternate is more about
conditions precluding a return to that field i.e. worst case including technical problems such as single engine, as mentioned above on one engine we could not do an autoland if the engine failed before arming the approach mode. So no, minima for approach and departure have no comparison, but if you are going to depart you need to know where you can go if you should not be able to return.
PP
edited due too much cabernet sauvignon