Is vinyls the plural of vinyl?
This is a lovely peevological case study. In the first place, of course, the “rule” is a doubtful one at best. Vinyl is a mass noun, like beer or cheese or glass, and as such, it doesn’t have a plural. Not having a plural is basically what being a “mass noun” means — a mass noun refers to stuff that comes in variable but conceptually undifferentiated quantities that are measured rather than counted.