They could perhaps implement meta reviews, which let users rate reviews. Note That:
* perhaps the ratio of misleading ratings isn't necessarily high enough to render the system ineffective (iow, it may be just noise), but in order to know that, it appears to me that the meta review would be necessary.
* it wouldn't stop people from trying to game the system (which lead to the idea that even if meta review was there, its effectiveness would have to be tested, maybe by using... a meta meta review?)
Apple has done this for years. "is this comment helpful" and then the reviews can be sorted by most helpful in addition to recent. i'm pretty sure most helpful is the default as well.
I guess this wasn't too far fetched an idea. Google engineers must have thought of this before me as well, which means that they must've a good reason to not implement it. I wonder what it could be.
* perhaps the ratio of misleading ratings isn't necessarily high enough to render the system ineffective (iow, it may be just noise), but in order to know that, it appears to me that the meta review would be necessary.
* it wouldn't stop people from trying to game the system (which lead to the idea that even if meta review was there, its effectiveness would have to be tested, maybe by using... a meta meta review?)