Of course, pairing beginners with beginners presents problems, but never pairing beginners with beginners presents problems too -- like preventing experienced students from getting to work with other people at their level. It seems to me that the real solution to the problem is to make sure everyone works with everyone.
Actually, I addressed that in the blog post. One way I have seen it handled is that practice is divided into sections, with one for beginners to train by practicing with seniors, and another section where they train by watching the seniors train with each other. The seniors get to practice with each other, and the beginners get to see the techniques performed at a high level of skill. The beginners benefit because they develop an eye for good technique that they can bring to their own training.