Exactly... somehow the politicians have become experts in that regard. The most likely reason is that safety and PROPER use of the road (ie: at a speed for which the road is designed for, for MAJORITY of the drivers and cars) are not a topmost concern when the government decides (speeding tickets, raised insurance premiums, essentially the money-talk counts a lot as well...). Thankfully, our cops have decided that the law is quite bad and allow faster speeds, more in line the the actual road design - they are humans as well, after all and they see the absurdity of such low speed limit on such great roads. 130km/h is the most common speed that I personally see and hear about from people I talk to and sure enough, the stats confirm that such speeds are indeed quite safe (Ontario has some of the safest roads, at least on this continent).
If anyone claims "people will always speed" and go 10-15 over, then I'll say once again... What if the speed limit was 150 km/h? Would everyone drive at 165-170? What if the limit was 200km/h? Would that produce speeds of 210-215 by most motorist?
People will NOT always speed, but will always want to drive at speed that feels safe for the road and weather conditions. It has been widely observed and agreed around the world, that such chosen speeds are between 120-140 km/h. Hence our initiative. We don't want people feeling like criminals when driving at 130, and since most of us are driving exactly around that velocity, we want this to be recognized and legislated (it. 120 limit with 10-15 km/h tolerance).
Those wishing to travel slower, can still do so in a slower lane designed for slower (and larger) vehicles.