Well others may get by without using fortify, but once I learned to fortify after the first hour or 2 of gameplay, I never once failed a hack (I got detected by hostiles while hacking a couple times but thats different). Is maxing fortify worth it? proberly not, is a single extra point in an already unlocked skill worth it? yes.
It is not like you are short on praxis points anywhere nearer the end of the game, I got every single aug I was interested in, and ended up putting points in stuff I just didn't care about/use.
In the last couple chapters of the gamet here are lots of level 5 systems, and without fortify the trace goes through other systems as if they weren't there, fortify drasticaly slows them down and it even has an effect if it isn't finished, as long as you start the fortification before the start the hack, itll slow them. Also although nukes and stops help a ton, near the end of the game some of the highly valued stashes may require 2 or 3 stops to get through due to the size of what you have to hack, more nodes = longer hack time/more chance of detection, but also much more stuff to fortify and buy yourself time.
At the end of the day use whatever you feel like using, all I know is that I've used fortify and I've hack without it, and using fortify costs nothing during a hack, it has a dramatic benefit and saves from using any stops/nukes which allows you to sell them and make more money.
