To hit Shen in pro play, you wanted to hit his shield strength and base it off ally missing HP. THAT is a great idea.
So you nerfed the shield values at higher HP and made it scale up. Precisely what needed to happen. But you forgot to buff up the shield values to give it actual value when you ult someone at 40% HP (the max scaling value). So we're left with Shen's previously mediocre shield except he can't get that small value at a good time, and ulting an ally that low on HP usually spells out doom for them, because the shield does not hold on for very long. So, by failing to buff the maximum values on the ult shield you did three things:
##1. Stand United is now being used primarily for engage, where you wanted to steer players away from that LCS strategy.
Ulting an ally at near-full HP reaps more benefits than ulting them at lower HP now, since the shield values suck anyway and it's not worth timing the ult right to save an ally unless they're running away tagged with a lethal ignite. So his ultimate is almost purely offensive power now, which is the complete opposite of what we all wanted.
##2. Shen has become even more of a "win harder" champion.
Shen before these changes was a very situational champion, as he relied heavily on the performance of his teammates to be effective. However, the defensive uses of Stand United allowed Shen to turn around fights and turn losing fights into winning ones. Now, as I mentioned in point 1, it is an offensive tool that only pushes a lead rather than turns around a situation where his teammates are behind. So Shen now primarily relies on his teammates to be winning and superior to accentuate their lead, rather than being a champion who can be an influencing factor in whether they win or not.
##3. Shen's focus has shifted from the map to his lane.
The increased CD on his ult, as well as the issues brought up earlier, means that Shen players are actively being discouraged to look for fights to jump into since it's not worth the shield or its absurdly long cooldown. Paired up with the increased damage against champions (whoever thought this was a good idea really messed up, he's a lane bully now), Shen's kit now rewards him more for winning his lane than for helping his team. That is _not_ what Shen is about.
I originally thought that the Shen changes would mean he would be significantly weaker in this patch, but I realized something much worse has happened: **Riot has turned Shen from a supportive top laner to a tanky lane bully.**
Please revert these changes save from the ult scaling and buff the shield values. I'd even gladly give up the E buffs if it means that my champion retains his identity. Thank you.