I still dont understand the difference I guess. If you want to do something can't you just roll and if you dont get number you need just say I miss? How is that different from a normal d20 game when you say you want to do something and then roll and miss? It's just the order in which you say what you are going to do. One way or another the dice is going to decide what you do by rolling a target number, saying what you do before or after is just semantics. I don't think they are forcing you to do another action if you dont want to.
Well, if you say "I want to trip him." but the dice says "You cannot trip, but you can stab him in the knee or insult his culinary talents." then you do, I suppose, have the option to simply do nothing and declare your trip attack missed, but it's would be a silly thing to do when you can simply stab him in the knee and actually have some effect with your action.
So I see what he is saying.
OTOH combat, particularly melee combat is a chaotic affair, so I think I'd be okay with a result that said "You tried to trip him but his footwork was too good and you had to settle for mocking his coconut shrimp."
I do think I would have a problem with completely disconnected results however.
"I drop the remains of my broken sword, hunch up behind my shield and charge, trying to shield rush him over the cliff."
"Okay, you picked his pocket and tied his bootlaces together."