It has never existed on the server, at least as long as I've been around (so since late 2011). It hasn't been "abused", thus, because it has never actually been implemented. Not that treating it as it is in-setting would actually qualify as "abuse".
There's a lot of misconceptions about what Detect Alignment actually does. I invite you to read it:
https://www.d20srd.org/srd/spells/detectEvil.htm
Essentially, it is detecting evil auras, and it's based on the hd of the character or caster level of the item (or class level in the case of divine characters like clerics). This means it isn't necessarily telling the caster whether a character is evil or not, but that they may be carrying an evil item, or is affected by an evil aura of some other kind (a spell, perhaps).
Recognise also, please, that in our case the table's numbers would be doubled, since that is how we treat levels narratively.
Now I also see people thinking it stifles RP or bypasses storytelling, which to me doesn't track at all. It stifles RP no more than Detect Poison does. Detect Poison lets me "bypass" various skill checks and the storytelling of figuring out whether someone (or something - food, drink, potion, etc...) is poisoned, if you want to look at it that way. Heal spell stifles RP because it lets you bypass the treatment of wounds and the RP of recovery.
Not having detect alignment leads to stupid situations like where the Radiant Heart was once lead by a favoured soul of Bane (claiming to be a paladin of Tyr) who was also Dreadlord of the Zhentarim secretly for several years. Now that is probably the most egregious case (which was forunately remedied by DM Narshe eventually), but it wasn't the last time something like that happened. RIdiculous infiltrations of organisations that shouldn't happen still do to this day.
I'm not going to point at anyone or anything in particular, of course, but imagine for example if a priest of Milil infiltrated a sect of clerics and blackguards of Iyachtu Xvim. Now, Xvimlar are hyper tyrannical (like the banites before them), and won't just invite someone to their sect without a proper background check. Indeed since the clerics can cast Detect Good, it makes a lot of sense that they would do that in regards to a new prospect.
Or Leiran trying to infiltrate the helmite Everwatch. You might easily see a Detect Chaos being cast in this case. Leira is admittedly dead, but the example stands.
Or, as is even more common, "secret" evils befriending paladins even if they aren't directly infiltrating (Yeah, I put "secret" in quotes, because in so many cases it is so poorly veiled that Detect Alignment wouldn't even be necessary, but to call it out will get a whiny accusation of metagaming. Good gracious, I have become jaded about this...).
And it's not like Detect Alignment doesn't have a potential counter. We even have Non Detection as a spell ingame (which a lot of people seem to think is doing different things than what it intends to do, but that's another topic).
All in all, you guys seriously need to stop seeing the setting we are playing in as getting in your way, and instead treat it as an opportunity to play within the framework presented. Limitation is the mother of creativity. Look at what Oarthias said.
I have a lot more I could say about why we
should have Detect Alignment, but I'll leave it at this for now.