I don't recall Callaway being in financial straits. Maybe I'm foggy with my memory, but the only big deal was with their lawsuit against Titleist re: patent infringement.
They have, for the most part, been somewhat innovative in their design philosophy... whether or not it has translated to overall improved performance aspects is a different discussion altogether.
But as a great salesman and mentor once told me, the sizzle is what sells the steak, it's not just about the quality cut of the meat. Doesn't hurt that they have a legendary spokesperson in Phil Mickelson serving up the sizzle.
He seems to do more for Callaway than Jason Day and Dustin Johnson combined are doing for TM. Then again, the marketing ignorance of TM supersedes anything positive gained from three of their most relevant superstars (Rose, Day and DJ). Imagine if PING or Callaway had them in their stables.
Maybe these companies are surviving because they're not recklessly hellbent on being #1.