Q: Same townies visit community lots
It might be that as long as your business is a low level, only a limited number of sims will be allowed to appear. Only once you've gained a few business levels, more different sims show up.
However, this would *only* explain why a certain limited group appears at one business. But for another business, the group ought to be different. You shouldn't see the same sims at all business lots all the time, I think.
But, as I said at the start of this message, I cannot be sure that this is how it all works. I'm just guessing.
~ an invisible Popular aspiration
~ a great deal of gossip memories about the playable sim owner, employees, and their playable friends,
~ a dining loyalty token
I backed up my game in case anything went wrong, and deleted these. It helped a great deal.
(For anyone who tries this, I strongly advise against deleting memories of "Met Sim A". From my experience long ago, deleting or even adding that memory caused a jump bug problem and confusion in other sims in my game.)
Those townies still come, but not as much, and other sims I who hadn't been customers now come to the business.
I'm guessing that their invisible aspiration to be popular was/is a strong motivating factor. The most annoying sims are also nosey and intrusive, so it makes sense they want to know all about the most active playable sims in the game.
On the other hand, your experience with the "Met sim A" memory is a bit wonky. Adding such memories is indeed risky, because you may not give the right information with each memory. But deleting those memories should never be a problem.
On the third hand... which game are we talking about here? I have never heard of traits as "nosey" or "intrusive" in The Sims 2. So somehow, some stuff is being mixed up here...