That's certainly one reason yes. Another is that the physically connecting the chords with the movement of your arm is important, and if you use pedal to allow yourself more time to find each chord, this movement is not as refined as it should be. Each group of three chord is one movement of the forearm, not three.
To tag onto this comment, the pedal allows a distinct "cheat" in technique. Very minor movements can be "wrong" and covered up by a pedal (particular during a heavily pedaled section). Practicing without the pedal allows you to hear this, particularly if you have trouble feeling it. The more minor the movement/error, the harder it is to pick up, and the more likely you will need multiple senses to discover the source of the issue (ie- ear picks up an error that would have been missed using the pedal, and that was too small/fast for you to 'feel' it).
Minor errors don't sound like much, but as repertoire gets increasingly difficult, they can become a disaster waiting to happen. This is also particularly true when transitioning from practice to performance--the added stress/anxiety can make a minor error explode on stage.