You mean numerically speaking? My gut instinct tells me the opposite. I think you’re just coming up with particular contexts that make it seem that way. When you consider all of the simple, concrete things, they’re usually countable.
That’s what I said about grass. It’s a simple concrete thing that’s easily countable. It’s only in a particular context that grasses aren’t easily countable. Yet “grass” is apparently a perfect example of a non-count noun. The only difference I can see is that the only time most people bother to think about grasses at all is in that particular context. Aside from that the word seems to behave like every other noun I can think of.