Why, it's self evident. Great style, a real suspension, instead of a pogo stick, rarity,.. heaps of stuff, but like i said,, this was,"in my view, opinions may vary", as yours obviously does, or did you miss that part of my post.

The site is "named" Datsun 1200, but is devoted, in practice, to the basic model grouping B10 /110 /210 /310 with a nominal focus on the 1200's ['70 to '73] as well as the lookalike '74 to ?? utes

I wonder how you came up with the "prehictoric" part when it comes to wonderfull, fully adjustable, easily lowered [for free] front suspension design. Is it because the design dates back to the 30's?[or earlier] Hell,the rubber tyred road wheel design dates back to the 1860's but you happily use this pre-historic component. The only problem with wishbone suspension is the cost of manufacture, particularly in a car who's main selling point was its low price. [& great style] [opinions may still vary]

Disc brakes for 1000's are only an e-mail or a phone call away. I had mine delivered, all nice & brand new, within a short time after my first enquirey, so i don't know about this "hard to get" part. It wasn't hard for me.
The best part is that it is a straight-up, bolt-on deal. No need to change pogo sticks or ferret through wreckers looking for Commodore calipers, Mitsubishi rotors & other model Datsun struts that need spring seats to be changed.
Fitting ventilated rotor disc brakes to my beloved B10's is a much simpler job than doing the same thing to a 1200. Perhaps you should step up to a Datsun 1000 & enjoy the diference.
This thread has a nice ute for sale, perhaps you could give it some thought.