I think it's a pretty good analogy but I can think about lots of others. There plenty of products out there that are dangerous if misused. I seem to remember something about hot coffee and pets and microwaves
The axial design has other problems. It actually requires you to create the second bend yourself, to avoid gas going back to the filter, like Jason mentioned. In my opinion this is much bigger danger as the volume of gas that can accumulate in the filter is much larger.
If you look at installation instructions, most units that utilise axial or r-shaped housings require you to create gas trap when installing it.
As far as the plates sparking, for it to happen you need either some metal debris to come into the cell and get thrown above the water level, or the plates touch each other.
If the unit is installed after the filter like it should be, then you shouldn't get any metal debris at all, let alone the fact that they will short out the cell in the part that is still in water, because they would have to come all the way from the bottom. For the plates to touch each other, the clips holding them together must break or they must bend.
This is a more likely scenario if the water has stray currents and the edges get worn out. However by the time this happens the cell would've been operating for years, so any problems with gas trapping would've been resolved.
In a scenario where the pump is shut off the gas would push down the water much quicker then what we see in this particular example, so your cell would turn off within a minute or so.
The mechanical switches are also prone to tampering. Believe it or not, I've seen commercial models with housing completely melted/exploded, because the flow switch broke and the operator decided to just tape the wires together instead of replacing it. They were lucky it didn't injure anyone, and the damage to the unit was in the order of 10000 for the cost of a simple flow switch.