This wouldn't be a buff per say. Cost efficient wise etc crit wick would be no stronger than current Warwick. It would just make him more fun to play as you can try a few more builds on him.
It wouldbe a buff if you were currently building triforce on him. But most don’t
Crit works on volibear, shen, poppy.. if your kit is hybrid and benefits considerably from auto attacks it shouldnt matter. Why should his ultimate disincline us to build crit. The reason was because I'd be op if it did. The easy solution was to just remove crit from his ult. I think had they come across this idea they might of added it in the first place. In which case none of this would not even phase you guys since it would have been implemented from since the get go. People don’t tend to question things that are already in place and tend to work, they are seen as naturally being there for a reason. Its usually things that are missing. Hence my query. (of course you just could say the inverse but I think that’s a bit less common, where in something is there and people want to remove it).
I think the devs would have allowed warwick ult to apply crit if it weren’t for the fact that you could theoretically get like 4 crits in a row. Which would be insane especially while under suppression.
If they implemented percentage crit dmg and spread your crit damage over your auto attacks, then at 20% crit your 5 autos would essentially be as if he just crit once since 100/5 = 20%.
Which would be a bit more balanced. But still a lot ontop of all the other on hit effects. and still leaning on the op side of things.
Though tbh if you go with crit your less likely to also get wits end or botrk. With this buff you won’t feel obligated to get that. I mean people are centering everything on the fact that warwick’s ult applies on hit effect. Yet if your ult gets interrupted it was short lived and you put a lot of resources into something that may not come through. Having %crit increase would give you something to fall back on. Kind of like how riven even if she misses her ult (mind you kind of hard to miss) she still got use out of her ultimate since it boosted all her spells.
Your just banking a lot on getting an uninterrupted ult which won’t happen so much at high elo hence why you don’t see warwick so much in tournament play since people know how to counter it.
Now, this is where my idea comes in to give critwick his savings grace sort 2 speak.
A champion that benefits so much from attack speed shouldn’t be adverse to building more dmg to complement it. They go well together. In fact on top of his W he has more attack speed than he knows what to do with so the next logical thing to get is ad/crit. His ad scaling isn’t that great so might as well get crit. To maximize dmg you want a certain ratio of attack speed to damage.
A lot of people say to build witsend on Warwick but tbh I think black cleaver makes more sense with botrk. Tack on trfiforce and voila. This has more synergy IMO. Since you can reduce their defenses with ult for botrk.
But if you go with my example of botrk, blackcleaver, you can use ult to apply black cleaver. So instead of getting wits end next get a crit item. The crit synergizes better with lifesteal too. True wits end does synergize with your q overall it probably breaks even, althought triforce’s 30 ap would probably be better seeing as how q has such a high ap scaling getting ap is probably better than magic pen.
Particularly vs creeps etc.
Warwick shouldn't build ad? First off he's an auto attack champ. If you have autos you benefit from crit. In fact when you aren’t so much interested in ad but what to make the most use of all your attack speed crit is the thing to get.
Sure wits end botrk work. It will remain as such even with this buff. It will still stay great on warwick even with this change.
A lot of people say to build witsend on Warwick but tbh I think black cleaver makes more sense with botrk. Tack on trfiforce and voila. This has more synergy IMO. Since you can reduce their defenses with ult for botrk.
But if you go with my example of botrk, blackcleaver, you can use ult to apply black cleaver. So instead of getting wits end next get a crit item. The crit synergizes better with lifesteal too. True wits end does synergize with your q overall it probably breaks even, althought triforce’s 30 ap would probably be better seeing as how q has such a high ap scaling getting ap is probably better than magic pen.
Particularly vs creeps etc.
Now just tack on a reworked version of atmas and add spirit visage then you have really synergistic build.
Warwick shouldn't build ad? First off he's an auto attack champ. If you have autos you benefit from crit. In fact when you aren’t so much interested in ad but what to make the most use of all your attack speed crit is the thing to get.
(Devourer) 
or 
then you can switch out 
