I think they're suggesting the seller should understand the risks of their undertaking. If they didn't do their due diligence it could end up being the case that the offer they take was the "worse" offer because the person making it couldn't back it.
That there are other considerations for a seller aren't really relevant when the post is about bidding just higher than a round number to win it. Just as explaining how you won the bid at 2k lower by having a cash offer and writing a nice letter and being accommodating with their move out times is irrelevant to the round number argument. The story of bidding 701k is clearly in the realm of "all else being equal", nudging the price up a relatively insignificant amount can have a significant effect.
