The thing is, by just removing the rule without placing a "limiter" (that still, no one would follow), you give BNs leniency and mappers more of a choice in the representation of their map. As normal, these things can be modded out if they are too much for their respective difficulty, just as all subjective matters are. By limiting these patterns, we're limiting the potential of rains downwards from what it currently is. As I said, no one follows this rule, and it's been working absolutely fine. If the rule didn't exist, no one would point any of this out. The offending material is modded out, and if not, it's DQ'd over for being inappropriate.