[omginternets]

With respect, you say this as though bluntness were a virtue.

I've found that putting a little bit of effort into form goes a long way in generating useful feedback.

Stated otherwise, it's about recognizing that we're not talking face-to-face, and that the characteristics of this particular mode of communication make it easy to misinterpret (often for worse) what is being said.

tl;dr: my favorite way to start a comment is "With respect, ...". It helps a lot.

[ensiferum]

Respect is not a given, it's earned. If you "respect" everyone it's the same as respecting no one.

[candu]

I prefer to extend respect, trust, etc. to others by default, with the understanding that it can be unearned. This way, I counter whatever unconscious or "first impression" biases I might have about what "respect-worthiness" looks like, and I find it leads to a much more positive / open-minded relationship with the rest of humanity than demanding others prove "respect-worthiness" up front would.

There are also degrees of respect, and accordingly there are absolutely people I respect more than others. (It's not a total ordering, though, nor is it a zero-sum game.)

[vertex-four]

Respect, in this context, is a measure of how much you give a shit about not hurting, embarrassing, or otherwise causing negative reactions for someone. It's also a measure of how much you're willing to attempt to understand their points of view, by extension of that. You can respect everyone by default in this sense, and you can respect certain people more or less.

[omginternets]

"With respect" has more to do with politeness than the form of "respect" you're suggesting.

And frankly, this brand of tough-love is really ill-adapted to semi-anonymous written discourse. I suspect the reason people appeal to it so much has less to do with its purported righteousness than the ego boost that follows from talking down to people.