To be fair, the majority of Lexus customers get good service and Lexus are consistently better than most dealers but the bad experiences do occur. However, it can be argued that its all subjective and possibly dependent on what service you've had before.
When you get pampered by your local dealer and go to another Lexus dealer to find that their service isn't up there, it makes you feel that the service is bad - however, it was probably still much better than a Merc/BMW dealer. Having said that, it also depends on the buyer. Some buyers are naturally fussy and want everything to be perfect - therefore, more likely to be unhappy about something that didn't go quite as well as it should have. For others, they just want another car and aren't overly fussed with its condition etc.