Within consumer tech, it's more like "Plan to throw it all away; you will anyway."
I used to measure code lifetime in half-lives at Google: the half-life of most of the code there was about a year, meaning that after a year, 50% of your code will have been deleted. It's pretty accurate: by the time I left after 5 years, about 97% of the code I'd written had been deleted. Ironically, I'm told that my one contribution (after 10 years) that still exists is an attribute-renaming CL that I wrote over break at a team summit; basically the whole team agreed it was a good idea, we would never have a chance to fix the problem later, so I just went and did it before the framework got too entrenched to change. Meanwhile stuff I slaved over for months, sometimes even stuff that was directly sponsored by a VP (who is no longer there) or got commendations from the CEO (who is also no longer there) was gone within 1-2 years.
I used to measure code lifetime in half-lives at Google: the half-life of most of the code there was about a year, meaning that after a year, 50% of your code will have been deleted. It's pretty accurate: by the time I left after 5 years, about 97% of the code I'd written had been deleted. Ironically, I'm told that my one contribution (after 10 years) that still exists is an attribute-renaming CL that I wrote over break at a team summit; basically the whole team agreed it was a good idea, we would never have a chance to fix the problem later, so I just went and did it before the framework got too entrenched to change. Meanwhile stuff I slaved over for months, sometimes even stuff that was directly sponsored by a VP (who is no longer there) or got commendations from the CEO (who is also no longer there) was gone within 1-2 years.