No one is saying to go tech. Learning how to calculate your gas is open water skills 101; why folks in this thread are against this is a little concerning. Moreover, diving doubles is not Tech diving.
However, IMHO, "pony's" are considered "Tech" because now one has allowed themself to pick up a single staged tank at a shop that might not have been analyzed correctly or analyzed at all. Let's consider that the open water diver does not know about analyzing their gas or diving different gas mixtures. This mistake could lead to picking up a tank that has the possibility of deadly consequences more so than having one set of doubles or a single 80 filled, especially at a busy shop that also does tech and rec diving.
Nevertheless, all I am advocating here in a New Diver thread is for those who ask essential questions, as OP has, to continue asking these questions and urge on the side of human factors and safety. If that makes me uncool, so be it.