"al-Qaeda decided to deliberately contaminate the opposition & deter western arms to the moderates"

"...Many of their followers are believed to have joined up opportunistically (huh?) because the front had more resources and experience than the other groups.With that trend now apparently starting to reverse and more resources being routed through the "moderate" groups, al-Qaeda may have judged it timely to remind the jihadists where their loyalties and objectives lie, lest they be lured away.
Knowing that the west is nervous about providing the Free Syrian Army and other "mainstream" rebel groups with serious, balance-tilting weaponry for fear that it may fall into the hands of the radicals, al-Qaeda may have decided deliberately to contaminate the entire opposition by association, and deter western arms to the moderates, in order to preserve the jihadis' ascendancy on the ground ..."