I agree with everything you said and realize that a lot of us can be just critical bastards.
There is however a difference when doing an original song. The "mistake" or "incorrect pitch" is something that they own and is part of the integrity of the original recording. As in a painting, a misplaced brush stroke is forever part of the masterpiece and becomes part and parcel of the composition. When a forger or replicator sets out to copy that painting they will also incorporate the misplaced brush stokes.
On the other hand with a cover, people are so used to hearing the song in it's original form that when someone else does it there is to some degree the expectation for a duplication of the original.
I have heard from you two recent covers that sounded like the vocal could have use just a wee bit more polish with getting the songs learned and rehearsed a bit more.
All I am saying is you got it so close that with just a bit more rehearsal of the song you could come off as quite the crooner.
Keep in mind, I like your work, and I wouldn't even be wasting my time typing if I didn't.
You got chops and plenty of them. You also have an outpouring of tunes. In the short while I have been on this forum I think I have heard 4 or 5. Impressive.
Now I am no singer, so in a sense have no right to comment...but what the hell.
I am no fan of perfection and studio trickery. To me it takes all the life out of the music. Nowadays in pop music there seems to be a lot of flawless shit.
One of my favorite examples of an imperfect tune is ZZ Top's Brown Sugar. In the intro you can plainly hear him blow it, then he recovers from that and goes into the tune.
It is imperfect and flawed but awesome. To this day in every live show he repeats the same mistake.