Interesting thread, to say the least. Not calling this specific poster out at all, but you posted all the above links in response to Ironworker, and I read them.
I think you two are talking about different things.
First link, you referenced the sentence below the first photo. That link is about welding aluminum with a spool gun attachment. Not sure it'd apply to what the discussion is here.
Second link seems to disagree with what Ironworker is saying, but not in a "absolute" sort of way. Seems to be more general.
Third link, the sentence you reference simply says a push will result in a " smoother flatter weld bead than when using a drag angle". Not that it's "better" or the "correct way".
Fourth link, Professor Marty, agrees with Ironworker.
Fifth link says push "improves coverage of shielding gas". But also says on "thin mild steel welded horizontally" it doesn't matter. Makes no mention of which style penetrates more. Now, in the "butt welding" link on that page, he has a video of how to do it, and he's pulling. So not real clear which way he thinks is the best, IMO.
Sixth link: says " Pushing usually produces lower penetration and a wider, flatter bead because the arc force is directed away from the weld puddle." Even though it recommends pushing on thinner metal.
Seventh: As you said, but isn't all that clear, IMO.
So not sure many of those examples are refuting what Ironworker is saying. One definitely is, one is irrelevant because it's a different material, some are agreeing, and others are ambiguous.
Again, I think you guys are not exactly talking about the same thing. I seem to remember someone claiming you push because the gas "blows debris out of the way", which is darn sure incorrect. I suppose that COULD happen, but it's not WHY you might do it.
Thank you for helping me prove my point.
My point was....to show that there are different ways of skinning a cat, and that what I'm suggesting "couldn't be further from the truth"....isn't carved in stone.
As far as aluminum being different, it's just less forgiving. Steel mig can be done with a pulling motion, but with aluminum it's not-so-good. The only real difference is that aluminum NEEDS better gas coverage, and pushing provides that. So, that means that it also provides better gas coverage for steel, as well.
Why do you think that several of those sites said that pushing the gun provides better gas coverage? Because it doesn't? It's got to do with the angle of the gun. Sounds logical, no?
Some experts say that pushing penetrates more, provides better gas coverage, etc., while some say that pulling penetrates more, etc. I can guarantee you that with my pushing method (oscellating), that I can get as good of penetration as anyone can using a pulling motion....and a better looking bead, to boot.