Old car drivers drive cars that need additives in the gas. The lead was a lubricant, and old engines ran better, and longer, on leaded gas.
They didn't just add lead because it made the gas prettier; there was a reason. I would suppose that today there are other additives that can reproduce the lubricating effects for those old cars, but old car hobbyists are niche and you're not going to find those products at Walmart, whereas there's always a local airport somewhere nearby.
I'm not defending leaded gas, but I think vintage car enthusiasts do it not because they're being stupididly misinformed and contrarian, but because they're trying to keep their engines running well.
Thomas Midgley Jr is the same guy that invented leaded gas and also invented freon (chlorofluorocarbons). Imagine being the architect of not one but two of the greatest environmental calamities of the industrial age.
And he also died from complications from polio. Not actual complications mind you, he was ensnared in harnesses he made to get around after having suffered from Polio. Made worse by his poor health having worked on TEL.
While putting in a new generator is absolutely a better idea, that means it's not the original car. Plenty of classic car (and computing and video game and music and any hobby) enthusiasts run original hardware on purpose. Where's the fun in building an Apple IIe if you use a flash drive instead of the hard drive? Where's the soul in listening to The Four Tops on a digital recording instead of the vinyl master? Why play Sega on a flash cart instead of the original cartridges? Why drive a classic Civic if you're trying to drop a K20 in there?
New stuff is objectively better. A 4Cyl Mustang makes more power these days than a V8 from the 90s, more so for older models. You have to be a little irrational to put that amount of time into running something just because it's older.
Where’s the fun in building an Apple IIe if you use a flash drive instead of the hard drive?
Not to be that guy, but the Apple IIe didn't have a hard drive. External tape or floppy were your only storage choices. The real cool kids had two floppy drives, so you could pirate games directly disk-to-disk.
I think you misread their comment; they weren't saying people they know are putting on new parts in old cars, they were saying people they know are maliciously putting leaded gas into new engines, presumably to "stick it to the libruls".