Consider yourself living on a nice, new sim of the mainland. You're happy with your small parcel, nice seaview, perhaps, good neighbors and then happening this: a new club is opening its gates.
Worse, this club has many camping spots, to fake traffic and also quite some visitors with the result that its eating up all possible traffic alone for the whole sim.
The result? You're busted. You cannot use your property anymore, because teleporting and even logging into your home becomes a new kind of adventure. "Is the sim already full or is at least one slot left for me to enter?"
So what can you do about it? Of course, you could tell the club owner to leave. "I am soo sorry, but I want to stay here, I like it and beside, I just own 4096 sqms of land and don't have the money for a private sim." Bummer. So he's eating up the whole traffic of the sim and making it unusable with just his teeny, weeny piece of it.
The next logical thing for you? To abandon or sell your land - don't think you can sell it with profit, by the way, good buyers take a look at the sim before buying it - and move to a private living sim.
So what should Lindenlab do about this kind of behaviour? Simple: they should make the tier traffic based in such a case. Why should I for myself finance the sim when some kind of business maker is only paying also a small share, but makes it unusable for the rest of us?