You're overstating the importance of bots.  The only inherently bad or unfair part is when they outbid you purely based on speed and get a deal you wanted.  Otherwise bots do precisely what a human tells them to so they can program it to trade fairly or like a jerk.  A human can manually set up unfair trades and scams and that sort of thing, just not as quickly.  So really the bot isn't that important.

I guess if your scheme involves 1000 trades, you'd have to use a bot but other than that, people are going to try and exploit the exchange with or without bots.

But nobody is explaining why a bot script would grab random values from a list and use them in buy orders.  That's no strategy.  It was obviously an attempt to crash the exchange.  This makes sense if you think about it.  Someone just sold off enough BTC to drop it from $11 to around $8 and then suddenly a few days later, there's a massive trade volume attack.  It was supposed to crash so everyone gets scared and sells off their BTC on mtgox.  Then when it hits like $5, the guy who originally sold off the massive amount of BTC buys it again for a lower price and waits for the price to normalize a week or two later.  Seems like the most logical explanation to me.

By the way, this was no price scheme.  This person easily lost 10x their money in fees.  That was like 1000+ cycles of their BTC.