I had just about convinced myself to stick with RAW on this one, then I had another thought on a situation upcomig in my game that supports what my player's POV (as described in the OP).
Youv'e got the PCs running up an incline on a trail, rounding a bend, seeing the trees part, then coming upon the bad guys who are just finishing up a raid on some civilians from the PCs' clan.
The bad guys (two of them) hear the PCs coming before the PCs get there (GM fiat--it's logical, but I'll change it if the Player surprise me and do something different than just tear-ass through the woods and up the road to where the ambush took place).
As the PCs approach, I'll have one bad guy hid behind a wagon that is on its side. The other will be in sight of the PCs as they round the bend (I take it the bad buy heard the PCs coming and maybe saw movement through the forrest at the bend in the trail). The bad guy will put his foot on a downed commoner and thrust his spear up to her neck. He's going to use this downed commoner as leverage to get himself and his bad guy buddy out of the situation by keeping the PCs off of them, then bolting, starting a chase scene, at sometime after some parley (at least, that's how I think the encounter will go).
Here's the question that came up while pre-thinking this scenario: I can have the bad guy use a Ready Action on the commoner, using some trigger that will allow him to run the grandma through at the neck if the PCs try anything.
The problem with the Ready Action is that it needs a specific trigger.
And, what I'm I basically talking about in this thread? Yes--a Ready Action that has multiple triggers or no triggers (allow the character to do as he will when he wills it).
What kind of a trigger would you give the bad guy, with his spear up to the commoner? You could Ready the action and say the character will run her through if the PC move past point X (maybe that the far-end of the wagon).
But, what if a PC throws a hand axe or a spear at the bad guy. I'd allow the attack, of course, but if the PC misses on his attack, doesn't it seem logical that the bad guy might run grandma through right there and then?
Yet, that's not the trigger that was set-up.
So, what I'm getting at is that there are situations in the game where the Ready Action is appropriate--but that there are many triggers that would bog the game down if you asked a player to name them all.
Don't you think that, with his spear up to the common's neck, and a weary eye on the PC's action, that the bad guy should be able to ram grandma through and take off running away from the PC's just about any time he wants to?
EDIT: Forget the Reaction. We're just looking at the Ready Action here. And, the question is: Do we really need triggers?
In my example above, shouldn't the bad guy be able to run grandma through the neck just about anytime he wants to (after his initiative). I can envision the character just declaring a Ready Action with no trigger. He can run grandma through if someone attacks him, if a foe gets to close--he can do it any damn time he wants to. Maybe he thinks he's stalled too long and just wants to blot, kicking off the chase.
There are too many "triggers" to list.
How would you run this scenario?
EDIT 2: Here's another simple example. You've got an archer, nocked and ready to let loose on anybody who comes through an open doorway.
The archer could ready an action to shoot at the first person through the doorway.
But, what if the first person through is a comrade?
Or, maybe it's an escaped NPC, slave of the PC's foe?
OK, so you say you'll ready the bow attack for the first foe who comes through the doorway, but then, a goblin comes through and not the bugbear the archer was hoping for. The archer can't hold his shot a while longer? He has to shoot? Why?
OK, so you say you'll ready the bow attack for the first bugbear to come through the doorway, but then, three of them come through and the third one--the big one that you've hit before--is the one you really want to shoot at.
OK, so you say that you'll fire at the big bugbear that you've shot before when he comes through the doorway, but he never comes. Two other bugbears, do, though.
In each case, shouldn't the archer be able to make a quick second decision as to whether to fire or not? If the archer really wanted to shoot at the bugbear, but saw three humans come the doorway, shouldn't the archer be able to say, "OK, I'm firing at the second human that appeared" and just forget the bugbear even though the bugbear is why he drew and pointed at the doorway in the first place?
Just how flexible should the Ready Action be?