I think certain people, especially those new to the scene making an e-name for themselves as a trainer, will try to come up with a slightly different version of the truth. Kinda like is someone was to analyzing a bunch of the best training systems like DC, HST, ect and point out why they aren't "perfect", but mine is.
To each his own. If the 5 x 5 packs on mass for you, as it apparently has for a broad range of people, then fuck what someone has to say.
Take it with a grain of salt and move on doing what works best for you. That's another thing. I see stuff like that every so often floating around in different forums, but what the fuck are you gonna do? No sense in arguing with someone over the net because most people have their heads so far up their asses, they won't see the ray of sunlight beaming in your post.
It all boils down to what I refer as the "yeah, but's":
Joe Average: "I put on a ton of mass with 5 x 5"
Trainer: "Yeah, but it must've been "newbie gains"..
Joe Average: "No, I've been lifting for 5 years, and it works."
Trainer: "Yeah, but you must've been doing a killer cycle."
Joe Average: "I'm 100% natural"
Trainer: "Yeah, but it's nowhere near optimal"
Joe Average: "Fuck you dude, whether it's 85% "optimal" or 100%, I've put on 7 lbs and my strength's through the roof."
Trainer: "Yeah, but I'm just saying that when I saw a study featuring an untrained duck-billed platypus, the muscle biopsy showed minimal hypertrophy when digging a hole using 5 sets of 5 reps using his bill.