They probably have a bulletin board plastered with anxious kiln-sellers. Large, worn out industrial models often rust away at the junk yards. Ceramic kilns are built to achieve a far higher temperature than burnout needs. Walls are thicker than necessary, and the interior is correspondingly smaller for the floor space it takes up.
Top loaders are uncomfortable.
Imagine having a top loading oven in your kitchen. If you stack molds, you may need shelves, and in any case you cant peek in and see the lower molds or get to them easily. Sometimes it seems that no matter what happens to them, the elements survive. I built a small electric kiln for testing clay formulas about 12 years ago. Several times smoke bellowed out of the vent.