Presumably the seller's agent, who is profiting from this phenomenon, is the one advising the sellers on the market, what is a good price, what is an acceptable

Presumably the seller's agent, who is profiting from this phenomenon, is the one advising the sellers on the market, what is a good price, what is an acceptable offer, etc.. You can't expect the average seller to have their pulse on the market in the same way agents do. It appears that there is a good chance that the selling agent knows that the house could be sold for more, while at the same time advising his clients that it is an acceptable offer. While the decision is ultimately up to the seller, I believe the agent is obliged to act transparently and in the best interest of their client and whether that is happening here is not clear.