I would assume he's referring to the lack of lateral branching and or the distance between the internodes( where each new leaf and shoot forms on the main stem).
Bushy and branchy is better for all aspects of the cycle,be it for yield,cuts,canopy control or all of the above.
The perceived issue could be either genetics or not enough lighting.I like to use 4' t8 flouro shoplights the twin bulb kind.They provide adequate light to achieve the desired rates of growth for me,your mileage may vary a bit.
Hope this helps,ya don't have to spend a lot to get a lot back.