It's a compromise. It may be one that you're apparently willing to spit in the face of, but it's a compromise nonetheless. A genuine mystery element is the Super-Soldier Serum; we don't know how this would react with the Hulk's origin elements, and the willy-nilly nature of the injections seems to be screwing around with Blonsky's anatomy way before he makes things worse with his transformation. Since we know in the comics that the Super-Soldier Serum in one dosage can enhance musculature and whatnot, it's not a far cry to say that abuse of the serum could lead to the body growing abnormally. This happens in cases of steroid abuse all the time. In this case, Blonsky seems to have his spine and skin mutated; seeing as how he's injected there, it's not surprising that his body shows signs there first.
The fact that it wasn't just mainlined into him via some IV is where my use of the word "compromise" kicks in. The spine probably didn't have to be accentuated as it was, and his skeleton didn't need to go out of control. As a matter of fact, the hair didn't have to disappear, his skin didn't have to go transparent, and he could have been the same height as the Hulk. That these were done insinuates that the crew at least tried to keep in line with Betty's original claim in the comics- that Blonsky had turned himself into some unholy abomination of the natural human form. You may not like it- heck, I'm not a fan of the look- but they tried within the confines of modern society's view on the improbable and the believable.