So, foes should never be surprising?
That's not what he's saying at all.
The statement 'I don't think all foes should be surprising' is not the same statement as 'I think no foes should ever be surprising.'
And you know it.
I think every foe should have the potential to be surprising. I think the players should know some information about foes, but there should always be the possibility that they don't know nearly enough.
Having the possibility and completely concealing which foes are minions are not the same thing at all.
When the DM says "that's a minion" (regardless of whether he does it directly or indirectly, people aren't all that stupid), he's saying "there won't be any real surprises here".
This is true if and only in encounters where only minions are ran.
I don't worry about encounters that don't exist.
If the players do not know minion status right away (and it's not as if they won't figure it out fairly quick), the PCs will still drive minions before them while they hear the lamentations of their women. Minions will still accomplish their purpose in life. They just won't be immediately killed in the first two rounds nearly every time by the area or close attacks like in a game where the players auto-know their status. Sometimes, they will be killed cinematically one minion at a time just like in a Bruce Lee movie. That doesn't happen as often in the "players are entitled to know" model.
Standard encounter design for published adventures usually spreads the starting position of minions out. Blasting all of them with area-close attacks at the beginning of combat isn't really a possibility for a well-designed encounter anyways.
Again, I don't worry about occurances in encounters that don't exist.
Of course, this also brings up the question:
Is having an encounter where the players blast the minions to bits with bursts a bad thing? That question is subjective, and only answered by your group.
Do you really not see a difference there?
I see a difference between 'realistic encounter' and 'false example used to prove a point.'
You see a man on the street. He's good sized. Is he an ex-navy seal, an ex-high school wrestler, or just an ex-burger flipper that ate a lot? If you wouldn't know in real life, why would your PC know in the game?
I do not know about games of D&D you run. But in every game I've played, they don't consist of gamers encountering people on the street and then engaging in combat.
Instead, they consist of capable combatants encountering armies of enemies that are determined to bring pain.
As such, is it plausible for capable combatants to look at an opposing army and pick out the lieutenants from the privates? The officers from the seamen?
Hell, I've no military experience but I can tell. So... someone who fights for a living probably has some greater insight than that.
When you add elements to your combat that say "alert, this is a minion", you turn the game into a game of mechanics and dice tactics, and away from a game of choice, wonder, and possibilities. There are enough metagaming knowledge elements in combat without adding more.
But, you're not adding more. You're reducing unecessarycomplexity by offering the possibility of understanding which the easy opponents are.
See, if players are given an idea of where to put the big guns, and where to put the light guns, then they have a choice that they can make correctly. However, if you don't reveal any clue at all, then they're not actually making a choice. They're being dudes at random, and if they make 'a mistake' then it's only out of ignorance.
So... how does that make it a game of choice? It's no more a game of choice than Deal or No Deal's case selection. Giving players the opportunity to have information allows them to -use skill- in the game.
Notice, that does not mean spoonfeed them information every single game on every single monster. Such a rebuttal is simply mistating the opposing case. What it means is giving the players the opportunity to acquire that information before they start blasting foes, so that they can possibly make informed decisions about foes they blast.
Again, you haven't answered the question:
What's so exciting about minions that concealing their minionness adds to the game?
Not hiding traps.
Not concealing strong monsters.
Not concealing the secret plans of your big bad.
Concealing minions. Answer -that- please.