It won't ever become "common" or even really that widely accepted as legit. My main reason is it takes WORK and TIME and most men just don't want any sort of commitment to something that takes either one for a body part that is not readily made visible (like the arms, shoulders, chest...the "big three"). The other big reason, is because of pill companies. My honest opinion is the pill companies will always keep Penis Enlargement from being seen as legit to MOST men. That's because, the guys who try pills (pick a popular one) take a bottle or a few, and realize they made ZERO gains.....then think pills=ALL Penis Enlargement and won't try anything related to Penis Enlargement ever again. They then, go tell their buddies "ha ha YEA I tried that stuff once...just a waste of money!". Their buddies then realize because their friend who "knows" got burned with that "bigger penis stuff" that it's all just a scam.
Sigh, ignorance is bliss eh?