IT's not that they don;t produce heat, it that they follow hte laws of sphysics and still only produce heat at a COP of 1. Meaning that 1 Watt in rpoduces 1 Watt of heat. While infrared wavelenght energy cna make you feel warmer from a short distance away, you still need ot heat the space and a heat pump iwht a COP of 2-4, will be much cheaper to oeprate even if you need ot keep the home 2-3F warmer because thre's no infrared.
Now, if we're comparing heat strips, to oil or propane, now the energy costs are more comparable. But then again, if your a tree hugger, since 75% of our electricity comes form fossile fuel, you want to reduce CO2 emmission, you want to use gas and oil as mcuh as possible. 80-98% efficiency when heating form those. A power plant might be 95% efficient thermally, but needs electricity to operate it's own pumps, fans, lights, etc. SO subtract all that plus the effciency of the generator and transmission, and only about I think 25-30% of the energy in fossil fuels makes it to a home. So you need a COP of maybe 4 to break even with a HE natural gas furnace.
95% is absurd
actual efficiency of 42% for a modern coal-fired power station.