Can we calm down about the Jinx W change?
This is obviously just a tuning issue, but let me give you something to think about, so we can have a framework to understand why Riot would consider this change.
How many times have you heard "ADCs suck this patch" since... what? S4 or S5? You can attribute this to general whining, but they have been in an awkward place in the meta since at least S5 (and I would even argue S4). Riot has expressed interest in making ADCs more viable, but also to hone their role a little more too. So what is their role? Simple, really. They are meant to put down ranged dps--consistent, high damage over time. Most of them have very low mobility and/or CC, so they are very vulnerable, especially against assassins who can output similar dps or just delete them outright.
Itemization is another frequent topic for ADC balance, and Riot has expressed interest in finding ways to make crit part of the ADC identity, and this can be seen with several of their changes this season across champions, masteries, and items. When you think about the proposed Jinx change to her W (which allows it to crit), it becomes clear what they are going for with said change.
So I reiterate: This is just a tuning issue.
We've all seen the video where her W one-shots an Aatrox with 1700 damage (after resistances!), and there's no way this is going to make it to live. What I suspect is going to happen is that they will nerf the crit multiplier on her W as well. Here's a basic look, ignoring resistances and the RNG side of actually getting the crit for the moment.
https://i.gyazo.com/0b45883538242cc4f85371ee348d4be8.png
Current PBE: Full crit application
300 AD 50% Crit (with Inf Edge) 210 + (300 * 1.4) = 630 damage (non crit) Crit W, 630 * 2.5 = 1575
If they reduce the crit multiplier by 70%, so W crits do 1.3x by default (before IE), then with IE looks like:
630 * 1.8 = 1134
Assuming equal stats, but no IE multiplier 630 * 1.3 = 819
It still hits like a truck (mostly due to very high AD), but that looks a lot more reasonable than ~1600 dmg.
Let's move from hypothetical to actual.
Level 9 with 
Base AD 74.4 + 8.55 (runes) + 8 (Doran's) + 70 (IE) = 161 total AD Crit chance = 20% Crit multiplier = 2.5
W rank 5 (max it first) 210 + 140% AD = 435 Crit W = 1089
With proposed W crit multiplier change Crit W = 783
Assuming equal stats, but no IE multiplier Crit W = 566
Keep in mind this is not accounting for masteries, armor's damage reduction, or any other factors that are more context sensitive. The proposed change is roughly 28% less total damage when you crit, even though the crit multiplier looks heavy-handed (it actually isn't). At these values, the W is still a strong buff to Jinx that encourages her to build crit, but Zap! isn't quite so oppressive when it does land while still being rewarding for landing it.
It's also entirely possible that they will just nerf the AD ratio on her W so she doesn't get to double-dip on the AD she builds when she crits.
Using the above example and a 1.0 AD ratio instead of 1.4,
Rank 5 W = 210 + 161 371 * 2.5 = 928
Still seems a little strong to me.
1.0 AD ratio AND -50% crit multiplier 371 * 2 = 742
This is a little more in tune with my previous suggestion, except that it makes her non-crit W strictly weaker. I don't think this is as good of a solution.
After all the (very simple) math here, I hope I've made the point clear: It's a tuning issue, and I doubt Riot will let it stand where it is now on the PBE.
Can we all relax, and just provide positive feedback/suggestions instead of raging at something which isn't even live yet?
