Plastic Degradation- 40 Micron bar

Q) http://www.cseindia.org/node/3705

It says here that thinner plastic (below 40 micron size) is difficult to recycle than thicker one- can someone please explain why? As far as I know, the degradation of thinner plastic is easier.

A) The answer is in the same article, which I reproduce:

Two primary reasons for increasing the thickness of the plastic bags are:

(i) The cost of the production of thicker bags is higher which would inevitably lead to a decrease in the production of the bags by the manufacturers and purchase by the customers. 

(ii) The second reason is that thinner bags are more difficult to recycle as opposed to thicker bags. This is primarily because the thickness of the bag determines the strength of the bag to break into smaller pieces. The thinner the bag is the higher is the probability of its breakdown and mixing with the soil which seriously deteriorates the soil and marine fauna.