Doesn't really make for much of a challenge if every time you get in trouble you can just lock the door and relax.
For example guards are chasing you and you can just lock them into a room or go through any door and seal it off?
Monsters are after you but you lock a door and they can't follow you any more? Your safe? End of threat?
If you want to keep your victim from escaping, just paralyze them.
Now, this would be fun if you could lock a door, or move a dresser in front of it to clog it up for a bit, then they would have to break the door down to get in, but it would be too much work for them to pull off especially with cells. Maybe in TES6 when they get rid of door teleports to cells we could do something like this.
Did you read my suggestion? Implement it for houses that you own, not just random houses you can run into. It'd provide a little refuge, and perhaps you could grab some extra potions/weapons from your containers before going outside to meet the fight again. You wouldn't be able to stay in forever, not only if they went with my guard-lockpicking idea, but because you can't fast travel from within your house, so you'd have to come out eventually.
Coming out would be even more inevitable if Perez Hilton was an NPC.