Now, while I can understand taking out abusable things, I think something should be done about balance.
Here is an example, I enter the room and this is what I find (2 rares, telos, a bone giant randomboss and a unique I've already killed and a bunch trash mobs). The combo is so crazy there is no way I could survive without stair dancing, considering forcefield + tons of buffs allows me to survive just 3-4 turns. Fact is, without star dancing I could press quit and delete the savefile as this is not an optional quest. Situations like this might happen several times during a run (on none at all if you're lucky).
Enemies can already grab you, block the stairs and hit you with several debuffs that prevent you from using the stairs, in fact I don't know if I'll be able to clear that room anyway.
What I'm trying to say is: is good to take out abusable things to make the game more about strategy, but if a 20h run can end just because RNG decided so, than I'm not sure about it. Maybe change the way a level get generated so that you're guaranteed to have some space, be able to dig etc.
You need to cheese the game when the game is cheesing you, otherwise you just die and that's is.
I would even say that it's ok to nerf the stairs on normal and nightmare but not on insane, considering the horrible monstrosities the game can create.
Just my 2 cents, cheers!
http://i.imgur.com/bgGYs2o.jpg