Sometimes a restaurant just has a bad day too. For example, during a trip about a year ago, I had two lunch ADR's at Le Cellier, about a week apart, at which I ordered the same meal (can't get away from my favorite). Both meals were right when they opened for the day, so they weren't full or backed up in any way. The first one, everything went perfect. I had a great server, my food was cooked just the way I like it, drinks refilled before I could ask, you couldn't have asked for a better meal in any way. The second trip, my server was all but non-existant, I only had one glass of soda, the food was so overdone as to be inedible (but since I couldn't find my server, I ate it anyway) and it was the worst meal experience I've ever had at Disney, bar none (well, except for the Jolly Holiday Dinner show fiasco, but that's another story). Now, if I'd only had one meal or the other, I might have posted a very slanted review - either positive or negative. But since both meals were during the same trip, I saw the restaurant at their very best and very worst.
As far as the poster who asked why people comment about the server, my two experiences at Le Cellier bring that right to the forefront. A good server makes a good meal better, by bringing your food out the way your ordered it, by topping off your drink without you having to ask, and basically anticipating any need you might have. They are at your fingertips without hovering over your table. A bad server makes you wait 45 minutes to place a drink order, even when you are their first table, makes you order your food with your drink order so they don't have to come back, doesn't check the food before it comes out to make sure it's the way the order was placed, doesn't ask if the food was OK, doesn't top off your drink or even ask if you want dessert, and makes you wait another 45 minutes after you finished eating (I timed it) for the bill. A good server can save a bad meal. A bad server can leave you not wanting to go back even if the food was OK (which mine wasn't).
So I read all the reviews and try to read between the lines. What is just the opinion of the guest, what is a fact, what could have been a one time thing, do I see the same complaints over and over from different guests . . .all of these play into whether or not I may try a new restaurant or stick with my favorites.