To start with, the fact that the manufacturer includes the instruction set and address space size before the heat-up time makes me pretty skeptical. I get that its hackable, and that's cool and all, but as with all "smart things", I care about the "thing" part way more than the "smart" part. I can implement a PID controller in about 20 minutes (maybe an hour if I need to bit bang the pwm output) on any number of microcontrollers; that's the easy part.
Also, the USB-C power supply is going to be nothing but a headache. I already have drawers and drawers of usb cables that can't handle the current I want to use, now I need to keep careful track of my soldering cable, which only performs at 60W over USB (and at best 90W using a barrel jack supply)? And the iron doesn't even come with a power supply, so you have to go source that too. It may be $40 for the iron, but then its another $10-40 for the power supply, plus (as you say) an appropriate stand, brass sponge, etc, etc. Suddenly, the dedicated station like the (very affordable Hakko FX888D-23BY) starts to look pretty good.
The pinecil seems like a good thing to keep in your crash bag, but it feels a bit like refusing to buy a power drill because your swiss army knife has a screw driver.
My criticism is that, as a first soldering iron, you shouldn't have to have a bunch of background knowledge just to know what parts are missing. They should at least sell a kit with all that stuff.
I guess that's fair for someone who is completely new to the world of electronics such as teenagers or older people who just never really did a lot of tech stuff.
But for many tech-y people without a soldering iron the Pinecil is fine; I don't currently own a soldering iron and I've never really been into electronics, but the Pinecil would be brilliant for me because 1) I know about tech-y stuff in general, and 2) I do know the basics of electronics and how to solder. I think this probably applies to most of the sad losers on HN who don't own a soldering iron.
In general Pine64 is explicitly aimed at hobbyists and people who "know what they're doing" rather than the mass market.
Now that USB-PD triggers, and ESP32 Arduinos with USB-C exist, I think it makes a lot of sense just to use them for almost everything.
I've not had any trouble using a random usb-c cable or laptop usb-c charger. But I recommend the pinecil silicone cable for $4 that won't get burnt.
It can use type-c _or_ a barrel-jack DC adaptor.
I think it's thoughtfully designed.