It was one of the last known large-scale users. They were pretty durable and it was needed as they were used outside and in spaces with humidity, dirt, etc.

The final contenders came down to the MC9000, MC50, and MC430. The MC9000 was "too expensive" despite meeting all of the requirements, so the MC50 was chosen.

PS: I acquired an eMate 300 because it's quirky and interesting.