why don't we use glow plugs instead of spark plugs?

[dieselworks]

I used glow plugs on my recent engine build with medium success. Very reliable starting, but only with dead air in the combustion chamber. With my setup, any air seemed to cause the fuel to hit the glow plugs, boil and flow away without ignition. I put a sight glass window into the combustion chamber. It was interesting to see.

I think a really hot spark plug setup would be better, but those are a bit spooky to me...

I messed with various different configurations in the combustion chamber and it seems like some had better re-ignition performance than others, or starting with airflow already in the chamber.

[ausjet]

I use a glow plug to ignite my kerosene fuelled engine. It works very well. Never had issues.
The specific style I use is called a hot surface igniter or silicone nitride igniter and not a traditional glow plug you’d find in a diesel engine.
12v, glows bright orange within about 1.5 seconds, no complicated ignition system needed, low current draw- less than 5a

crystaltechnica.com/12-volt-25-watt-mini-igniter-ml12-25-te150/