Yep, you don’t like how cast time res feels because there is an inherent issue with causality. When you use an ability and fail, you need to be able to learn from your mistake. Cast time puts you in a situation where you are stuck with very little control of your character for 2.5 seconds. 2.5 seconds is an eternity in this game. Players are constantly predicting what will happen in the next moment in OW but with the fast paced nature of the game and with all the variables involved, it’s impossible to look very far ahead.
With heroes that can teleport across the map, blink, go invisible ect ect, you need to be able to react constantly. You cannot lose control of your character like you do when you cast res. This results in no causality and causality = fun.
Brain has to identify mistake and want to fix it for next time. If brain can’t do that then brain get sad. 
Now, you’ll say “Oh, but there’s CC in the game!” and that’s true, but the causality there is to learn not to get frozen or hacked ect. You can react to those things. Why didn’t you shoot that Sombra and interrupt her hack? Why did you stand in front of Mei holding a sign saying “please kill me Mei!”?
Then you’ll say “Oh, well use your Reinhardt to shield you!”, but that’s hardly an infallible protection and also the location of the corpse is out of your control, if your Reinhardt listens and helps you is also out of your control. You’re seeing the issue here? YOU HAVE NO CONTROL. THERE IS NO CAUSALITY.
When you go in for a res, you are in effect putting your faith in the world around you. You rely on your allies to be smart and your enemies to be dumb. It’s 100% everyone else and 0% you. This is bad design. Teamwork is great, but teamwork by its definition should idealy be 50% you and 50% your allies.
So, how do we fix this?
Well, the skill expression should be placed into the ACQUISITION of the res ability in the first place rather than trying to nerf the ability itself with silly things like cast times.
What does this mean? Well… resource system??
https://i.ytimg.com/vi/ZmwOjHwhw9s/hqdefault.jpg
Or ya, shifting it back onto the ult would also be fine, but I like to run with the assumption that Blizz has too much of an ego to do that. Reverting would be admission of a mistake and we can’t have that! 