I also understand both sides. I can almost compare this to me preferring to talk to someone over the phone rather than texting, because words on a screen can sometimes be taken out of context. Therefore, when I critique I try to be as tactile as possible.
But...I consider myself as very much an amateur, so critiquing takes time. Essentially, the time the critiquee who has exposed their baby desreves. So I will be as honest as possible, postive and negative.
With regards to me receiving feedback, because I'm an amateur and have a thirst for learning in all areas of life, I want to be hit with everything, and really look forward to it. The more the better. Only then can I produce my best work possible. I have actually left a forum because the feedback was 99% positive.
The sandwich approach is generally favourable, but peronally, I'm inclined to question the person's honesty. I'd wonder if they're just dressing it up for the sake of the sandwich. I prefer Rick's salad approach. I don't like bread anyway. But everyone is different. It does take guts to put our work out there, but it also takes character to both accept and act on feedback, and take on board but chose not to use. I suppose it depends on how much the writer wants to improve or if they're just toying with ideas.