Pertaining blank flanks and the CMC

[StarSwirlTheBearded 356]

I have noticed that although the CMC seems to think that they're unique for not having cutie marks, I've seen tons of fillies throughout the series that are blank flanks.  Is there a reason that the CMC hasn't reached out to them?

[Ribbonfree 2,384]

It's implied that the CMC are older than the average age that fillies/colts get their cutie marks. So those other blank flanks depicted are probably younger and thus not CMC material.

[Rebel the Wolfgirl 5,616]

RIGHT! Anyways, here's how I see it:

 

The CMC are slightly older.

[pinkiefan1287 610]

Like @, said, most likely it has to do with there age. There is also the possibility that there aren't that many ponies who are to concerned with getting a Cutie Mark, like the CMC. 

[Scootalove 10,692]

I'd say that the CMC are older than the usual colt or filly that has no cutie mark, mainly the average age. They probably didn't want to join them or they never thought to ask.

[Adorkable 2,737]

Some don't mind the wait, the CMCs are out to get it NOW!

 

Also, as most have said, they seem to be intended to be older than the average Cutie Mark-less filly.