For all the claims that botting the MB is rampant, I've never seen any good evidence of it. Even when I directly invade the markets of people who are supposedly botting, I find they're really easy to beat and they just happen to be kind of active, making a few undercuts per day, which isn't even as many as I make when I'm really invested in this game and spend the whole day playing or whatever.

What I routinely see evidence of is that many casual MB users are instantly aggravated by any interaction with the MB and have a tendency to exaggerate how much of a problem it is because they're thoroughly upset. The system shouldn't be ruined for their benefit though, if it would even for their benefit. I definitely make items in large batches, so I often have more in my inventory I'm just waiting to post. If undercutting was limited, you'd post your item and I'd simply "undercut" by making a new post. The end result is a minor inconvenience for me and you're shut out of the market because you can't adjust the price of your item.