Among all the replies, you've mentioned most of my feelings in one form or another.
I think staff reviews here tend to be a bit forgiving. They're fine for the "just the facts, ma'am" stuff, but unless I've missed them I don't see too many that are negative. In fairness, what they seem to try to do is review based on the "level" of the line, meaning that expectations are different for NCL than for Crystal. But if the reader isn't on to the different classifications, they could read this stuff as apples and apples. But then, if they'd just look at the fares. . .
And, of course, staff reviews are generally written after free or heavily discounted trips. This shouldn't be a factor, but people are people. Plus, this website depends in some measure on advertising from the cruise lines. Again, it shouldn't matter, but you never know what might be happening, even subconsciously.
Beyond that, sometimes the reviews are so poorly copy edited that they make me scream. My favorite pet peeve is writing in the first person without signing the piece. There are many reviews like that in the staff section, and that's a no-no. In addition to signing first person reviews, all staff reviews should be dated with the original date and the date(s) of any revisions.
Reader reviews can be good if there are one or two fairly comprehensive ones that are recent (a real problem here, as somebody mentioned). Many of them are just gripe lists and pretty useless, just as are the ones that are Hallmark cards of effusive joy. If you're lucky enough to find a few fairly new, balanced reviews that seem to be in accord, you've hit the jackpot. Rare, though.
So, even though I look at them, we usually wind up going with lines we know we like, itineraries that interest us and dates that appeal to us.
Just like most of you.