Hum...
Monoculture is either the same crop on a field every time, or the same crop is a very large area. A single crop in a field for one season only is crop rotation, something that is absolutely not monoculture.
And it is inherently something bad, that's how the word is defined, if it's not extensive enough to be harmful, it doesn't get that name. It may be "not very bad" and normal, but it's bad.
What kind of experience are you talking about? Maybe I'm a candidate for having it. I dunno.