I think that's one of the biggest sticking points with Maps and iOS in general and I'm sure a lot of other people share your sentiment, myself included.
I'm not suggesting anything, I'm trying to make sense, in my head, at least, of how so many errors have gone unfixed for this long. That's not to say I think "this long" is too long but rather that it's not a simple matter of setting a threshold of x number of reports and then taking whatever corrective action once that number of reports has been reached that all have the same correction.
And obviously Apple didn't independently verify every single POI and road, etc. when they licensed the data; I assume that they assumed that it was good. And also obvious is that they were wrong.
I don't know what happens to reports when they receive them and how fixes happen and I haven't at any point pretended to know but it seems clear to me that it isn't a simple process and that the amount of time that's gone by with the amount of errors there are having not been fixed is evidence of that.
Well, even if they didn't want to rely on crowd sourcing long term, they could at least use it short term to get a proper product out there for us all. I suspect though that crowd sourcing is the only way to go for this sort of stuff, be it done directly by Apple or outsourced. Pretty sure that's how Google do it, isn't it?
It would be pretty safe too, wouldn't it? You can identify people from their iTunes account, so you can ignore reports from people who frequently report things that are contrary to the average report for that item (this would be a good place for a manual check first though), and people who've bought iPhones aren't likely to want to spoil the Maps service anyway, are they?