That's just the thing.. Except those technical reasons would only logically apply to regions where PSN exists and is supported. The issue with this game isn't just that they're making it mandatory after the fact... they're making it mandatory for countries which don't have PSN support officially. Making accounts in regions outside of where you are is against their TOS, and apparently in some regions you can't make an account at all unless you do so from the console itself. So if you don't have a $500 PS console.. you can't make an account.They have their own accounts!
How many of these do I need to post?! Sony aren't doing anything new to Steam that other publishers haven't been doing for years. The only difference here is the requirement wasn't in place from day one, and people started Helldivers 2 without being asked to log in to their PSN account. We're told that was for technical reasons, and the game blew up in popularity so that's not completely unrealistic considering how hokey we know PSN can be.
Sony should have bit the bullet and left this particular game alone with that requirement and instead have just incentivized as many PC players as possible to create/link their PSN accounts through DLCs or something. "Hey link your PSN account and get a free x or y" and make it actually appealing to do so. Then focus on making it a requirement with future games.
They went about this all wrong.