Over on Hack & Slash, -C wrote a blog post called On How an Illusion Can Rob Your Game of Fun that reads like a manifesto. It belongs to a whole cross blog conversation that I haven’t really read up on. Maybe I will.
Basically, -C is ranting against a «quantum ogre» – a mythical encounter that happens no matter what. -C ends the blog post with the following:
What’s really terrible about the destruction of player agency in the above examples is the implicit thought that ‘your encounter that’s sooo cool’ is what makes Dungeons and Dragons fun. It’s not. It’s getting in that Dispel Evil on Strahd that slays him outright. It’s getting that critical on that dragon while it’s talking shit. It's taking down that frost giant at first level - not your fsking precious encounter. 
In the comments, some people argue that the quantum ogre isn’t so bad. I disagree. Here’s why. The quantum ogre is only bad if the players have information that ought to help them evade it and they cannot. But in addition to that, having to make a choice without any information is also bad. Thus, we’re talking about two bad things.
An adventure involving the quantum ogre is bad because the players’ choices don’t matter: either they don’t have enough info to make a meaningful choice or the information they have is useless since the quantum ogre will show up no matter what they do. They have no agency – they have no capacity “to make choices and to impose those choices on the world.” Either they cannot make a meaningful choice because they lack information, or they cannot impose their choice on the world because the quantum ogre shows up anyway.
Update: A comment by Trey on the «On How an Illusion Can Rob Your Game of Fun» blog post wanted to know about the differences between a single quantum ogre encounter and the use of random encounters. Both of them remove player agency and yet the sandbox proponents don’t decry random encounters. Why not?
I think there is a way to improve random encounters because the quantum ogre and random encounters exist in a continuum.
(The following assumes that players have some sort of information allowing them to make meaningful choices.)
The quantum oger is at the one end. No matter which way you turn, the oger encounter happens. Next to it, we find random encounter tables. No matter which way you turn, eventually you will meet an item from my precious list. Next to that, we find differing random encounter tables depending on the surrounding areas. No matter which way you turn, eventually you will meet an item from one of the appropriate regional lists. Finally, the last alternative I can think of is having no random encounters and only lairs placed on the map. No matter which way you turn, you will meet the appropriate item for this hex on my precious map.
What I’m trying to do is increase player agency:
I’m sure there are more variations. For my own games, I try do #3 and #4. Players get to pick the important encounters by choosing to explore the mountains where they need to fight a frost giant (#4). In addition to that, there are rumors about a white dragons (also #4 with partial information). What players don’t know is that the icy glacier environment also supports winter wolves (#3). In addition, the trolls are on a war path and thus I have added them to the random encounter list (this starts out as #2 but eventually moves to #3 as players learn about current events in the sandbox). This creates meaningful choices: If players don’t feel like fighting frost giants and white dragons, they can avoid the area.
Thus, I agree with Trey’s comment. Simply having a random encounter list is only marginally better than having a quantum ogre. Basically you’re just having more of them. The key is introducing ways for players to make meaningful choices and have those choices make a difference.
Update: Courtney has written more articles in his series on player agency. I recommend them all.
Update: More recommended articles I found by following links: