Now some folks may say: "Why don't you just get a regular-ass #AUI like a #NormalPerson?"
1. Simply because noone but the most tech-masochistic folks want to deal with like #coax cables, #VampireTaps, huge #MAUI boxes and rare vintage stuff + overhead to get a slow & underwhelming network experience. Pretty shure neither @ncommander nor @TechTangents would either.
2. The few late-era #10BaseT-based AUIs do exist but they are long out of production and thus quite expensive. And if you are on #10Base2 or even #10Base5 good luck finding a still working #switch that isn't sold by a #scalper like #ersazza way above #MSRP+#inflation!
3 An AUI is just an Interface port / media converter similar to #SFP & GBIC and necessitates a NIC already inside the machine.
4. AUIs are not just long outdated but also way more inflexible, whereas basically anything from an #Apple2 up to the latest #Android-#Tablet can be adapted cheaply to do #RS232 #serial and send AT commands to a #Modem.
5. Twisted-Pair Ethernet is cheap, commonplace and still supported and pretty much forwards- and backwards compatible. 10BaseT will run on Cat.3 but also on Cat.5 and even Cat.8 cables (In case one wants to hookup a vintage computer on a 40GBase-T port for no reason but to see if the switch does negotiate proper 10Base-T.
6. Because it's useful...
7. as said before: AUI port would be nice to have but not necessary...
8. it would allow Network access similar to #dialup abeit without the need for existing #PSTN infrastructure like @c3isdn has...
Habr
Kevin Karhan 
Der Entgegner (Aka Ratatöskr)
Jesko Anschütz
pnpnerd