I don't know why other people crave flexible nibs, but I can tell you why I personally do. It's because they are capable of producing works that cannot be accomplished with a "nail" or manifold type nib. Yes, I'm sure some people do "abuse" and spring their nib (although with any common sense this would seldom-if-ever happen), and I'm sure there are those who seek out flexible nibs because they are convinced that in a week they will be writing like those infamous Namiki Falcon videos if they only had a flexible nibbed pen. As Mickey pointed out, that is a pipe dream...a good flexible fountain pen is a tool, and will enable a person to develop skills in styles that are not possible with a nail, manifold, stub, or italic nib. Anyone not interested in developing skill in those styles would have no benefit from acquiring a flexible fountain pen. (I know, some nibs are a hybrid of broad nib and flexible nib. I have one of those too); but for me the most enjoyable fountain pens are those that are xxf or xf, yet are capable of flexing out to about a BB shaded swell. I have yet to find a modern fountain pen that will do that for me, so all of my flexible fountain pens are older vintage ones with 14k forged gold nibs. Of course this is not everyone's cup of tea and that's cool, but those of us who enjoy a bit of calligraphic flair to our writing love using flexible pens. Another "benefit" that I like is that a flexible nib does not "have to be flexed". With only a little practice, it's quite simple to write with the tines closed up in thin line format, so to me I can emulate the writing of a stiff pen with a flexible pen but not the other way around. You could not produce anything that resembled any form of English Roundhand (or Spencerian or Ladies Hand or a multitude of other styles) with an inflexible nib, without considerable doctoring and double-lining. So, that's why I love them personally. Don't get me wrong, I like stiff fountain pens too...but the reasons that I personally prefer a nice flexible nib are those above.