You'll really need to be a lot more specific because stating there was no planning to a city like London or Amsterdam would be really myopic. Perhaps not on the level of Haussmann's plan, sure, but there's been quite a lot of planning in every city. Particularly because most cities have been severely damaged and then rebuilt according to a plan (e.g. London after the 1600s fire, but also after the second world war, both to rebuild bombed areas, but also as part of an expansion of the city where large parts were built completely after the late 1940s UK town and country planning acts, which is not dissimilar to the late 1910s act after the first world war.)
I think there's a huge continuum of "planning". It's true that even cities which have mostly evolved organically also have probably had various bits of planning applied to them here and there, and there's a big difference between that and a city where the majority of the city's layout was planned as a whole, and rigidly controlled over time... [E.g., Tokyo, which is hugely "organic" city, even now, but which also certainly has had parts of it planned, and continues to have some central direction to its development.]
I'm a fan of organically evolved cities, but planning isn't some sort of poison that ruins everything in any amount, and indeed it can be done in a way that really works well. Look at Edinburgh, where large parts of the central city are the result of several eras of large-scale urban planning (all centuries ago). It's one of the most beautiful and livable cities in the world.
I think one has to be much more wary of modern efforts at city planning, in part because the modern obsession with automobiles means that modern city plans are almost always oriented around them—and this is pretty much universally poison for a livable city.
