Mind you, bonding isn't the same as pining. The emotionally messed-up women aren't really bonding to the men they're seeing, they're pining (and that's why they stumble upon one "emotionally unavailable man" after another, it's not the guys...it's them!). The difference between true love and "love" is the latter comes from a place of lack, neediness and fear. And it's not the sex that "bonds" them to the guys, it's their insecurities. A mature, emotionally healthy woman who is strong in her self-love and boundaries can love deeply without the roller-coaster emotions. And their love comes from a place of security and joy.
And to many others, FWB is not merely about sex either. There is the "F" part that is also prominent in the arrangement. These people might like to hang out and do activities that are not remotely related to sex together. They are great friends and yeah, the benefits don't hurt either as long as they are on the same page. It is a form of relationship whether or not you or they want to label it. The difference is in the expectations and levels of emotional investments.
To some this arrangement is a perfect way to prepare themselves for a real relationship when they are ready. It is a great way to practice relationship skills and heal to those who have just been out of a long-term relationship or marriage.
The only condition for it to work is both are on the same page and one isn't more invested than the other. The equilibrium might be thrown off, though, when one develops more feelings than the other and as a result is wanting more from the relationship. That's when complications usually start to ensue. (And if you are wondering why he's pulling away, you might want to check if you are a "frog farmer")
The fact you're reading this perhaps because you are under such predicament, correct? You want to know if you have a chance to turn this arrangement to something more serious and permanent.
My stance is yes ... yes ... yes! (UPDATE: I just helped my client/reader turned a FWB of almost 2 years into a serious relationship, he stepped up and claimed her after she practiceds my tools.)
It's a limiting belief to think that relationship can only happen a certain way. As I and many others have personally attested, there are many routes to relationship or commitment: some through sexual flings (or even one night stands ... gasp!) and some through friendship first and some other through FWB. As long as there is mutual attraction and chemistry, nothing can stop two people from being together.