Yeah, writing it off as just a trend is exactly what I did. I tried it on my old fireplace brick on a whim, just a small spot to test. The difference was crazy, way more than I thought. It didn't look new or fake, just cleaner and the color popped more. I ended up doing the whole thing over a weekend.
My buddy was the same way, he thought it was all hype. He finally tested a patch on his basement wall that was just gray and dusty. The before and after was nuts, like someone turned the lights on. He said it brought back all these red and brown tones he forgot were even there. Ended up renting a sprayer and doing his whole rec room.