Why is the Adafruit motor shield incompatible with these motors/kit?

Hey guys, Arduino noob here. I'm looking for a readymade chassis to quickly prototype a mobile Arduino robot.

I liked the chassis here from Make.com - Robot Kits | Robotics Kits | Books - Maker Shed
I then looked into the Adafruit motor shield page on the Make website (Maker Shed: Official Store of Make: and Maker Faire since 2005), and it clearly states "The MotorShield V2 is not currently compatible with our MAKE Rovera 2WD or 4WD Arduino Robot Kit."

I can't understand why. I already have the Adafruit motor shield. Will I need to buy the official Arduino motor shield to get this working?

Its not clear - have you asked Adafruit?

Did some further digging under the FAQ section of the Adafruit shield.

"The motors used in the 4WD robot platforms from some distributors have a lot of "brush noise". This feeds back into the Arduino circuitry and causes unstable operation. This problem can be solved by soldering 3 noise suppression capacitors to the motor. 1 between the motor terminals, and one from each terminal to the motor casing."

This should work. Thanks for responding anyway!

Ah, cheap copper brushes probably...