No, actually resistive touchscreen is not 3D touch at all. You cannot do multi touch with resistive touchscreens; they don't respond to slight touches. They are just 2 dimensional screens activated by pressure. I agree that 3D touch is not the best name but this is because everybody tends to name everything 3D. In this case, it is very good name because it adds the 3rd dimension to the devices with 2 dimensional screens. Swipe actions are all in 2 dimension (x and y-axis) and 3D touch adds the z-axis (only positive or negative, though).
I don't think the OC was referring to multitouch, but rather how resistive touchscreens can measure different levels of pressure applied to them. For example, I have a Nokia N900 with a resistive touchscreen that I can draw with, pressing harder for a thick stroke and lightly for a thin one.
Exactly; however, if we're on it - it's a myth that multitouch is not possible on resistive screens. There exist resistive screens that support up to 10 touch points, and two-point gestures (swipe, pinch) without exact coordinates are very easy to get on most resistive screens.
When you lend your phone to my mom and she asks how to do something, will you say "just 3D touch that" to her?
The name is just a silly attempt to create a hype, "firm press" or something similar would be just fine. But yeah, it wouldn't pretend that it's a "new concept" then. It's just like it was with "retina" - my phone had "retina" screen years before Apple started to use that word.