They also had Relentless so could fire Heavy with no penalty (and other weapons). It wouldnt be outside the realm of possibility if Rangers ignored negative modifiers to hit as their special rule. Incursors do and they are a Troops choice for Space Marines and Dark Reapers do for Eldar. Rangers currently have none of their previous identity, they dont scout, or move better through terrain, they cant pseudo target characters and their guns finally got AP 1 which they should have from the start (all AP4 guns turned into AP1, Galvanic weapons decided they needed 6s to wound for it). So I can see Rangers ignoring penalties, they are meant to be marksmen.
That is my major problem with the 8th and (soon to be) 9th edition codexes. Skitarii were differentiated from Imperial Guard in 7th edition by being able to move and shoot without any loss of accuracy. That was reflected on the models with the bionic eyes, bionic legs, and no kneeling poses.
Now Skitarii work just like Imperial Guard with better equipment but no command squads. Ironically Guard can be better than Skitarii with shooting through Orders (no command points necessary to activate!) and Regimental Doctrines. It doesn't feel right. Rangers are supposed to stalk their prey for months without stopping. They shouldn't be relegated to backfield sniping. They should be able to move freely whilst shooting and not have to stop to use the Transuranic Arquebus.
Yes there is the Protector Doctrina Imperative and that's great but it costs a very scarce Command Point to activate. Meanwhile Guard regiments can "First Rank Fire, Second Rank Fire", etc. for free. 7th edition Doctrina Imperatives could be activated to affect every Skitarii unit in the army. It required some thought to pick the right one because it usually meant trading some Weapon Skill for some Ballistic Skill, and vice versa. That is a ton of army flavour lost by the latest round of uninspired game designers.