Well, I've heard conflicting stories on just how far along they were. The fact is 5 years worth of work was stolen, and I would imagine it was HUGE job to rewrite major portions of the code that could be sabatoged by hackers.
They didn't rewrite the engine. Think about it - no matter how strong your code is, you cannot stop hackers.
The best copy protection is broken in days, and released with trainers. The only other hacking that would concern developers is multiplayer cheats. Any engine built nowadays does not rely on security through obscurity, simply because the hackers will eventually figure it out. Time is spent limiting the damage that can be done by people who don't have access to the game server. Obviously valve is betting that HL2 will be a huge online game, so they'd have done their homework here.
Knowing this, why would valve spend several months rewriting code when in the end it will only delay
hackers by a few months at best? Add a punkbuster style app, and publicly released cheats are shut down within days anyway. There aren't going to be many more people making private cheats either - you still
need to know how to create hacks, and even with source it's not simple. For the source to be usefull, you need the same compiling tools that valve used, which are not cheap (or easy to find as warez).
Oh, and then there was the content leak. Thousands of files, with varying, but many recent (for the time) filedates, and a bunch of half-finished maps that put together couldn't amount to more than a few hours of gameplay. Even before E3 valve would have known Sept 30 was impossible.
Great, so take it out on the publisher, not the damn developers, especially not developers like Valve who have given so much to the gaming community to be treated like shit for missing a release date.
I was pointing out that gamers have justifiable reason to complain in general. I'd say the most complaining is
done about the publishers. As Crytek has shown with their missed dates, I agree gamers can go a bit overboard sometimes, OTOH, the 1.2 patch seems to be getting great response, even though it was pulled because it didn't work for some people.
The complaints against Valve are another story, that was more than just missing a release date. They compounded the problem with the 2-3 month code rewrite delay story that was false and
the ATi bundle.