Actually Crazed is an advantage not a drawback for most civs. Either you have Law-Mana (and many civs have so from the start) in which case it turns into a full advantage. (Movement boost + Combat boost 20% half of the Time isn't all that bad).
If not its free xp in the Battleground of your chosing.
You are really think Units turning barb is a bad thing?
For World-Units maybe. But only if you have no Law at hand. Normal units going crazy level your good units without big risk involved. (and one fight on a Tier 2-3 Unit is worth 3-6 XP even with good odds.)
Both is a plus. And clearly so.
As an added benefit Asylums produce Lunatics (which seem rather Cheap to build) and upgrade Slaves to Lunatics (not the worst thing with Slave trade or Slavery Civic btw.

) which are additional free sources of XP. Not many other places where you can build reliable! XP (since they always start with Crazed) for your already experienced Units outside of an actual warzone.
Let alone at the place and time of your chosing without much risk or another AI / Barb / Player moving his units with purpose involved.
You have to look at all things, true. But OO is not that bad a deal.
Its not as overpowered as stated here somewhere either.
Its a fairly well balanced Religion all in all which might! be much more powerfull on Maps with lots of Water. Like it should be and is designed to be.
If OO breaks your game in Multiplayer either change your Strategy (again: try against more experienced multiplayers and you'll see that cultists are not all that game-breaking as you think) or your type of Map.
FoL with lots of Forests is good as well. As is RoK if really lots of Hills are around.
They are designed to be just that. Full Stop.
Its all a question of settings. If they don't work out ok: Change them. Not the hardest thing to do.
Stack-busting Spells are a different matter and should be adressed comprehensively as a block and not via small isolated fixing.
I don't guess you whould like to argue that without a costal City or Water near OO is rather bad in comparison, whould you?
Oh and save for Lanun, Costal Cities are not exactly yery good in FFH 2 most of the time. (Or in other words: Without at least 2 or more Sea-Resources and lots of land in your fat cross costal cities rather suck. That includes benefits from Foreign Trade and greath Lighthouse allready if you dont get those costal cities are crap unless only 2-3 Sea-Tiles.

For Financial Civs it might be borderline acceptable but is still subpar.)
And guess what: Lanun is rather likely to get OO faster than you and rush you if you try that. They are the ones which have most incentive to go OO.
If you are Lanun and use OO its playing to your strengths and the game is designed for players to just do that.
Try Dwarves on a Highlands-Map with lots of Mountains + Hills and RoK and you'll see.
If you know Player-Lanun is in the game leave the sea for them and get them down via maelstorm Fireball and the like. No need to let them chose your Battleground. If you do: Your loss.
If you can't avoid costal cities because Water is everywhere you play the wrong map.

And want to hand victory to Lanun.