Those footnote costs would include replacing dated/broken hardware as well as up-keep. The cost of buying more servers would be tiny anyway. This was the release of one of the most anticipated games of the decade. One of the highest selling PC games of all time and Blizzard chose to skimp on hardware?
I've seen smaller companies double their number of servers for beta events when population demand called for it. When Rifts servers filled up at launch they brought more online within hours to let people play. When SWTOR servers became overloaded at launch, Bioware increased population caps to allow for more people to play. Blizzard undoubtedly had the resources to accomodate much more of the launch demand than they bothered to, but instead they said tough shit and let people wait in queues for hours or advised people to wait days to play.
I suppose my point is this (the optimist in me): Blizzard had the resources and ability to blow peoples expectations out of the water with Diablo 3 launch. They had the oppertunity to show the rest of industry how the big boys do their business. It would have cost them (an $18,000,000,000 company) next to nothing to show everyone else what is possible when you put in some effort and make a solid attempt at raising the bar. Instead, they went with middle of the road mediocrity and skimped in every place they knew they could get away with.
Even if they did spend the $ and really go balls to wall on their hardware for launch and after a while it was mostly unused due to dwindling demand it would still be money well spent. It's PR. It's showing all thier players that they'll pull out the stops because they can, because they want to produce something great and do their best to support it. Instead we get the impression that Blizzard only care about making $ and not good games with good support and good communities. Not everyone can be Valve
. Next big Blizzard game to launch will have people remembering how shit the D3 launch was instead of how good this one might be.
There will be a reply to this post with someone defending Blizzard's launch approach by telling me I was expecting too much and that I'm and entitled 12 year old brat. Some people are happy with below average.