Look at the changes. They solely target durations, and for stuns, they pretty much do their job regardless of duration, within reason.
Excepting the whole hog, accretion, and blizzard changes, the goal here is clearly to reduce total time spent stunned, with minimal effect on their actual effectiveness, availability, and overall balance.
If you think this isn’t enough, that’s because it was never intended to change what you actually wanted. The devs aren’t missing the point; rather, they’re deliberately choosing to not address it here.
Duration is everything for a stun, though
If earthshatter only stunned for .25s, it’d be useless
even if most of the values seem small, you have to think about it relatively
mccree loses about a 5th of his duration
ana and rein lose a 6th of their durations
mei and brig lose an 8th
time is everything in overwatch, and those fractions of a second add up
Much of the value of stuns comes from cancelling any current casts and making someone an easy target for long enough to be finished off, which usually doesn’t take that long. There are exceptions like sleeping bob, needing to follow up on multiple shattered targets with a mostly melee character, etc, but you’re not going to be substantially better off after a team shatter from these changes.
They are going to more deliberately address it with OW2. Probably new system like diminishing returns or CC stacking that requires the engine upgrades to work right.