Why does Toronto need a 65nm mode-c veil?

(Paul Tomblin) writes:

According to "Fly With Blake",
http://fly.blakecrosby.com/2007/03/t...ges_expla.html
the YYZ "Class C Mode C" airspace stretches out to 26nm, and now they are
going to make the ring from 26nm out to 65nm from 6,500MSL to 12,500MSL
"Class E Mode C", meaning you don't need a clearance, but you need to be
squawking mode C. [...]
Where is the need for this air space grab?

One may give the benefit of doubt to ATC and accept that it would
probably help keep airplanes separated. The effect is probably to
permit controllers to vector jets while mostly ignoring primary-only
radar returns, permitting ATC presume that the latter are below the
new ring.

In this day and age, how much trouble do you believe it is to get a
working mode-C transponder in the plane if one wants to cruise 6500 ft
up -- i.e., how many people would be inconvenienced by this "grab"?
(Note that gliders at a nearby field are excepted.)

- FChE