So we'd prefer a game without reactions? Without opportunity attacks? Without legendary actions? (maybe those are OK, they don't interrupt the turn as much...)
I'm curious about the psychology at work there. Reactions offer some off-turn options, some way for characters to stay vigilant and reactive as the enemy does things, a way to encourage seeing combat in your mind's eye as a changeable milieu even as the rules adjudicate that milieu on a round basis, etc. It can be a nice moment of power for a player when their off-turn action stops something potentially devastating from happening to the party.
It does shout "Stop!", but I guess...what's so bad about a player yelling "Stop!"? That's half the appeal of a 4e Fighter!
For me it depends. Like - an attack of opportunity usually doesn't change the outcome of the previous action, but adds to it.
But if you look at it, an attack of opportunity has the same "problem" as counterspell.
Because with movement you usually say "I go this way". But for attack of opportunity to work, you need to break it down into - I'm leaving the reach of that Creature- does that trigger an attack of opportunity? No? Okay, I continue my movement.
The difference to counterspell is, an attack of opportunity is something everybody has in their mind, because it happens regularly, everybody can do that from level 1, there are several abilities that add to the attack of opportunity, while counterspell is niche. Only counterspell needs the time frame between declaring to cast a spell and saying what spell it is to cast and no other ability interacts with the distinction of "declaring to cast and naming a spell".
But actually, I'm fine with counterspell and Attacks of Opportunity, even so I overpower counterspell by already declaring what spell to cast.
Silvery Barbs, Shield and especially Lucky, so everything that retcons a roll result, is what grundsätzlich my gear.
