The variation in the molecular weight of the raw plastic material alone results in variation that makes those sorts of tolerances pure hype or fantasy. If you look at the Lego design you see it is very forgiving, allowing for variation while still maintaining function. Also the acrylanitrile butadiene styrene material has a rubbery component that gives the blocks additional resilience and maintains a good feel while accommodating variation.
Think if all comment threads were like this?
Why Legos Are So Expensive — And So Popular : Planet Money : NPR
