DS doesn't want leader restriction for a different reason.
Do you really want to be more restricted? If restrictions continues to increase but enforcement continues to decline, be prepared to see no changes on the river.
What's next?
Mandatory use of a float?
Designated float depth (ie. must be two feet shallower than river depth)?
Mandatory use of fast action drift rod, 8wt+ fly rod, medium weight class, specific lb test line and hook size?
The main problem sits on the lack of enforcement, which all of you should be pushing for.
A poacher will still study, pass the entry test, obtain a licence, and fish in an unlawful manner as he or she wishes if enforcement is absent.
DFO's mandate is not to dig into an angler's tackle box. That is why it is reluctant to implement a leader length restriction.
Leader length restriction is not going to solve the problem. The solution has to come from the angling community, which should clean itself up before criticizing other sectors' wrong doings. A good start would be to develop responsible angling ways in the young generations.