Essentially there's two components.
1. Cuz VIPs get Vort/OSE for free, there's no Tryouts or anything for the classes. Lack of things to do means lack of CO activity/interest in the class.
2. Because there's no expenditure of effort to PLAY Vort/OSE (such as a Tryout), there's no activity checks or other means to get people to be active.

I actually preferred when there were some semi-superficial ranks like what the OSE of long ago used to have (LEGIONNAIRE/VIKING/MARAUDER/TITAN) because then there's SOME kind of persistent character element to the class. Even if the ranks held no meaning they were still a status symbol, and the rare occasion of seeing an OSE who actually ranked up was pretty cool. (though TITAN is currently used as the default OSS title, so meh)

Vortigaunt ranks i'm a bit more iffy on, though they could have something like what I mentioned for OSE where it's present as mainly a persistent status symbol. iirc those were Vortigaunt/Elder Vortigaunt/Grand Elder Vortigaunt, though I think there were a couple other ranks from WAY back in the day that i'm forgetting.

Vortigaunt needs to add back elder vortigaunt only achievable through its ranking system it had with a max of 3 slots or something but a hard AC that requires you to be active on it weekly or something, would be really cool but never added.

shit was really dope

yaknow back in MYYYYYY day Vortigaunts had to learn an entirely new language.

where vortiglock

2+ times it was tried, both times yielded nothing of worth, got scrapped.
there is 0 reason for a ranking structure past "why not" and the negatives outweigh any benefit it could have.

a "neat" thing to have requires work for COs, the COs COs, and their CO's too. You can't create a leadership if activity is not a requirement and the class itself is a toy in your mcdonalds box.

For the point of the argument, I want to point out the difference between a fully functional ranking structure and a "status symbol" rank structure. I don't know if the original suggestion was asking for a functional one or one like old OSE used to have.

A status symbol doesn't need to have any leadership attributes, COs, or anything special. It can function like low rank RF/UNIONs where they can get recommended at DB if they seem competent. Just like normal ranks, it's essentially an incentive to actually play the class, but it doesn't need to have any responsibility or privileges that come with normal ranks.

You can say a status symbol doesn't have any point but if you really want to make THAT argument you could also say that ranks as a whole are a status symbol and follow the same trend, just with a few added components of responsibility.