Earlier quoted context omitted.
I'm genuinely curious how the decision to use MD5 gets made. Who says, "hey, maybe we should use MD5." And then who responds, "that sounds like a great idea Bob." Seriously. I've known for years that MD5 is insufficient for hashing passwords and I'm just some random guy. This kind of thing really baffles me.
And nobody ever seemed to say "hey, maybe we should be using something more secure". Yahoo's been around for how many decades, and the fact they were still using MD5 in 2013 is just shameful. Yeah if it was some legacy code from 1993 you can probably excuse it, but I just can't believe after 20 years nobody thought it was a problem. I'm not really a software developer but I really can't imagine it being a huge change…
In reality, they're constantly under pressure to develop new features, fix reported bugs, move on to the next project, keep the site from falling over, etc etc.
And the ones who choose NOT to work hard aren't sitting around reviewing old code either.