Greater social acceptance of it would not actually be a good idea
I have to agree no matter how much I love masturbation and sex. I think accepting masturbation in society as a common free habit just like eating a chocolate would be nice and hot but it would also loosen the leashes that keep this society binded and makes us productive and prosperous, simply because all men (and even women) would have their minds on sex or masturbation looking at the girl working right across their desk or room or whatever.
However, I do believe that no matter what, the Internet culture in our lives is very strong and has changed our lives for the past 20 years dramatically. And Internet culture means porn culture also because it is so easy to find hot porn just like searching for something in Wikipedia. Actually Wikipedia can really supply someone with a good deal of porn to get him started considering that at the end of a hot-porn-babe article you can find her official website with a lot free material to watch. So, all I am trying to say is that no matter what, masturbation at least for men will, if not already, become a more common habit and more and more socially acceptable (it sounds bullshit to me when someone come to me saying "oh buddy, I don't watch porn. Not me"). How much acceptable it will be I don't know and of course that remains to be seen but I believe it will to some extend.