Just for me, since I seem to be the only one experiencing this.
Today I spoke with Apple support about it. The support person I chatted with was no help - he actually wanted me to ask each and every app developer about the problem. This makes no sense, as that would suggest that every app developer I purchased an app from on the App Store are currently colluding together to stop me from rating reviews helpful or not helpful. I highly doubt that, I think what happened is that the support guy failed to accurately relay my problem when he said he was contacting other Apple people about it. It would be a ridiculous thing to do, since this supposed developer created conspiracy still gives me the ability to both post and rate apps in the App Store.
I'm assuming everyone else has the ability to rate reviews as helpful or not helpful. I know the App Store reviews have given developers much more leeway to edit what appears on their pages, but I highly doubt that if I was banned from rating the reviews of apps, they'd leave me the ability to rate the apps themselves with a rating and a review.
I miss Steve.
