why do people help make old cars look bad

Years ago I picked up a 72 Demon... the grille was still original but it had a few cracks in it so I plastic welded them up and spent days afterwards masking and repainting it in the correct argent silver. Felt like it took forever but the results were worth it.

I eventually sold the car and assumed it went to a good home but less than a year later, it popped up for sale online looking pretty much the same except my labour-of-love grille had been completely blacked out and had a large R/T badge stuck on it. My head exploded but what can you do? Once the car is gone, it's gone. Demon R/T... sheesh. :(