a myth? rootbound is very real, you really shouldnt spread your experiences as fact.
1. Signs of a Rootbound Plant
The pot has been filled with roots and there is very little soil left
Because there is very little soil left when you water, it goes right through and drains out, nothing is retained
The plant wilts within a day or two of watering, because with very little soil, no moisture is retained
The roots are growing out of the drainage holes
The roots are cracking the pot
The plant is top heavy or way too big for the size of the container
roots like to grow down not around. by keeping ur plant in a tiny pot its not growing in ideal conditions. ideal conditions yield the most bud. of course as hedgehunter said, u can still manage in small pots, but thats at the risk of reducing your total yield.
here is some very real info on this "myth"? (i think not)
http://www.evergreengardenworks.com/rootball.htm
also a few images
http://www.weekendgardener.net/how-to/repot-rootbound-plants.htm