Not to spark of debate about it or anyhting, but although they do get too hot, there are some cases which requires its use, actually, and ways to work around its getting too hot and the humidity loss. I dont think we should immediately deem anything useless or completely unsuitable without finding out the circumstances and considering ways to make it work.
The main thing that may require the use of a CHE is usually low ambient temps, like below 75F. Snakes have really long lungs and even if the enclosure floor is heated to 90+F, the high end of whats acceptable, inhaling cold air can significantly drop its core temp. Heating enclosure floors through UTHs do little to raise ambient temps by any noticable amount, maybe except for inside a hide. This is when a CHE, IR lamp or radiant heat panel is needed more. It is especially relavant to people who dont use alot of heating and dont have a dedicated snake room, thus the low air temps. The high temps of the CHE are easily dealt with by means of a thermostat high up near the top where the CHE is. And humidity, well I do fine with a water bowl below and covered top. And there are numerous other supplementary methods you can employ to further increase humidity if thats still a problem.