Yeah. It's not always obvious at the beginning, though. In my second job, I didn't notice this until it grew to the point we couldn't really implement anything new without spending 90% of the time on the spaghetti the business logic became. My excuse is that we were all new at this kind of work, but the lesson is clear: just don't do that.
"Then model is like 80% the same, just use the same class!"