"That caused some consternation in the world of board game Kickstarters; there is a relatively low rate of fraudulent projects in this domain, so the necessity wasn't really felt."
I mean that is pretty narrow-minded, as if the rule was specifically added to target board game projects. It's the "why do we have speed limits? I don't speed!" argument.
No, there are dozens of low goal, bullshit projects (even creating perpetuum mobiles and the like) - that are perfectly within the rules! Why? Because their rewards never mention to deliver said miracle machine, but you get a thank you note or your name of a plate. So probably some people abused it by launching campaigns back to back and just scamming people out of their money.

Could it be changed for specific categories? Sure, but initially it was launched as a blanket rule.
 

I would argue that bullshit projects wouldn’t even be affected by the rule: You would simply make a new fake company selling a new fake product instead of using the same account several times. The interest of creating a “history” of successful projects only applies to people who actually plan to deliver and have repeat business.

Wouldn’t it be better to strengthen the rules against fraudulent projects rather than just allowing each creator just one of them?
 

Hmm, I guess Kickstarter could go with what you said, mark first projects as higher risk and push a successful history as something projects would want, creating a tighter bond and maybe allowing Kickstarter to later add some paid "upgrades" for parallel projects etc.
 

Seems like a rule with good intentions that won't actually do much good. Like you mentioned in the comments a scammer can just create a new business name to get around the restriction.

So this only hurts legit companies who work on multiple projects at a time.
 

I see Kickstarter and similar services as "virtual begging for money". So, in that sense, it isn't different than real-life begging. Some people/associations are legit. Others are scammers. That's it.