"We don't make cities truth to life"
In other words, place-making can easily fall into the trap of simpification while we do need "uncomfortable spaces" to make people aware of life. We need to foster meaning making by helping people to overcome the "cognitive dissoncance", (but I would also add, to cherish good emotions) that arises when unexpected opportunities and challenges are offered by a truly "flexible" public space.
Richard Sennett is somehow coming back to his very first book "The use of disorder" (1970) where he pointed out the need for places that encourage non-planned activities and the confrontation with diversity that may nurture tolerance and sociability.
As he clearly remarks in the video though, this is not something that can just spontaneously turn out but it requires on the contrary, for difficult it could be, a thorough consideration in design and planning.
"We need to break the mold of correlation between needs and satisfaction". This is possibly the most challenging approach to urban design, in the past but probably even more today when neo-liberal forces are increasingly compressing our "room for manoeuvre".
Uncomfortable Spaces: Richard Sennett on Urbanism