Criticising anyones singing is always problematic. Some things such as the ability to sing in tune can be judged with a degree of objectivity, other aspects of performance will be much more subjective. A singer may receive very different feedback dependent upon he type of club/setting they appear at.
This thread does illustrate one point, which is that in most circumstances people tend to be very reluctant to say anything negative about a singers performance. Whether this is a good thing is certainly a matter worthy of discussion.
Many people on this forum post videos on youtube, including some involved in this thread. Having watched a number of these I am sometimes amazed by the gushing praise for some performances which I have to say I have found pretty poor. Of course I never upset the applecart by going against the flow and being critical. It is the old saying beauty is in the eye of the beholder.
I play with a couple of friends and we do it because we enjoy it. We practice regularly and we give each other both support and criticism. We strive to be better, but as amateurs we make the occassional cock-up e.g. me changing the key without telling the others, but we are not getting paid and we do learn from our mistakes which seems to me to be a key point.
I know that to some the music/song is a matter for arcane discussion, but for me if either the listening or the playing is not enjoyable it becomes rather pointless.
john