The primary reason the software development field has evolved to be preoccupied with saving/re-using/inter-op code is because of the difficulty of building even the most trivial piece of software.
Unfortunately code hoarding is simply a reflection of the age-old human flaw of wanting to recoup sunk cost, you assume if you've invested a lot of time into something, it must be worth holding on to for as long as possible :)
If software was as easy to make as a piece of office stationary is easy to write on, no one would care about code reuse/saving/interop...you don't see anyone saving post-it notes or even excel docs for indefinite reuse.