I'd like to make it clear that I was ranting perfectly sober....jsut clicking back back and forth as the boss was walking around behind me.
I (and most) won't agree with what you said. The "proper" mountain shoes your'e talking about are just as bad for walking as "proper" road shoes.
Pick a friend who says he has bad knees and needs float. Ask him to stand up and move his leg directly up and down (like climbing stairs or pedaling). Does his heal move sideways? Does his knee move sideways? Does anything star to hurt if you tell him not to move his knee or heel? Note that his heal doesnt move around but only goes up and down.....but theres a good chance the heal isn't pointed directly back. It will alsomost likely be pointed at a slightly different angle than his other heel.
It's important in noting the difference between the heel moving in and out and having the heel be natually cocked to one side.
I use 0 float but only one of my feet is point directly forward.
Most problems with no float pedals come from user error. Then they go online and tell everyone how a certain pedal/cleat sucks. Its very very easy to set them up incorrectly and cause serious pain. IT band is comes most common, front of knee is second.
There are lots of "expirienced" people in cycling. I recently had cat 2 a guy bring back a sponsered frame that he was racing all season. It was at least two sizes too big. None of his expirienced coaches said anything to him.
You will find a brazillion guys who claim no float is awful and wrong because in 1987 they set them up incorrectly at home and couldnt walk down stairs for the next two months......obviously the pedal's fualt.
For the last 100 years dudes were racing completely strapped in, locked, and feet pointing forward. There were almost no complaints becuase the pedal didn't allow the user to make a mistake during instalation.