Here is why C6 point items are rarer than C6 effect items and why the candy cane is not a true coeff 4.
According to the French server, every single item has its own "weight" that controla how rare it is. This is the reason why point C6s are rarer than effect C6s.
The weights of the items are as follows:
C1: 2000
C2: 1000
C3: 300
C4: 100
C5: 10
C6: 1
The candy cane is referred in the code as a "coeff 7". It has a "weight" of 60, making it slightly rarer than other C4s.
Coeff 0 items and items in blocked families have "weights" of zero (like

or

after finishing the quest).
The combined weights of all the effect items are 61574, as for point items it is 158594, due to an abundance of C1 and C2 point items.
As the combined C6 totals for both are equal to four, effect items have a 1 in 15000 chance of being C6 (0.0065%), whereas point items only have a 1 in 40000 chance of being C6 (0.0025%).
So for every 65 C6 effect items, there are about 25 C6 point items.
With C5s, the chances of an effect item being C5 are 1 in 880 (0.11%), for points it's 1 in 950 (0.1%).
Point items have a 61.8% chance of being a C1, but for effect items, it's 45.5%.
If there were ten C6 point items, they would be close to the rarity of effect C6 items.