Totally agree with you and
@Torq regarding negative reviews. However, the other side of that coin is: searching for reviews for product X, if nobody bothers to post negative reviews, the product would look much better / positive than it really is... so, at times, negative reviews are actually a service to the Head-Fi community.
I definitely think that negative reviews, or reviews that include negative and positive observations, are important - especially at a community level.
And I think if I was a professional reviewer (i.e. it was any part of my job, or I was compensated for it, rather that it strictly being a volunteer/enthusiast thing) I'd still be willing to put in the time to write such pieces myself. I've certainly done it in the past. The disconnect isn't in not wanting to say bad things about something - as long as its an honest opinion I have no issues there at all (beyond some of the behind-the-scenes nonsense that sometimes then ensues). Instead it comes from what it takes (for me) to write a review.
Spending several hundred hours critically listening (as well as doing so simply for pleasure) to something like the Vérité or an Yggdrasil or the SR1a etc. is a pleasure. And getting to do so essentially risk free (in the case of loaned gear rather than stuff I've already purchased for my own wants) is enough of a perk to make it worth while.
Spending the same level of time to do a proper review on something for which it is immediately apparent either isn't for me (it might be excellent, but not
my thing ... the Meze Empyrean are a case in point there), or I just outright dislike, is another. And I don't feel good trashing products based on just a couple of hours exposure. Though if someone asks specifically, I don't tend to hold back - I just don't go pushing my thoughts on it (and often not even mentioning I've heard it) unless asked anymore.
I have come to a point where I generally won't audition, much less review, anything anymore unless it either a) has a high chance of being an upgrade to my primary rigs and/or b) is something that I might add/swap/buy myself for other reasons. Where as even just a few months ago I was quite happy to review gear that I had no intention of using myself or keeping (at least for any purpose other than future comparative reviews).
Even for gear I absolutely love, it's progressively harder to write feature-style reviews for. No product is perfect, but I dislike trying to find flaws in things if they don't crop up naturally, and sometimes that's the only way to have any kind of positive/negative balance in a review. Oddly, I find that happens more readily in stream-of-consciousness style reviews, which is likely how I will do all future reviews (excepting the SR1a which I have almost finished). Though I still plan only on covering stuff I have an active personal interest in buying for my own systems.