Well, clearly Sony entered the gen with the biggest chance to win... but they more than made some bad moves.
My view on the various wrongs of all notable parties:
Sony launching PS3 with high price point (Cell & BR) and very weak and embryonic online - big mistake, particularly in US. They're recovering but they went from sure thing to last in a blur thanks to almost totally mismanaging the transition from PS2 to PS3, particularly early on. Their poor marketing and lack of imagination in attracting customers also warrants a mention.
MS rushing to market and paying for it (RROD) and overly focusing on what US wanted (online and violent shooters) thus failing to capitalize globally on Sony's mistake (to be fair though their approach did do well in US - still is in fact).
Nintendo underestimating how long HD consoles would remain viable vs Wii due to specs, missing the boat in online and failing to work well with third parties.
Western developers for chasing gritty, violent online orientated titles in a mad rush to gain "some of them CoD sales" resulting in a severe drop in breath of options and style of games (which Nintendo filled to an extent). Of course this worked for some but I see the longer term impacts as being more negative. Also too many developers allowed "must have MP" and the fear of used game markets to influence them, with often terrible results. As many strong SP titles showed, get the game right, market it right and their is still a huge SP market. In fact, what I find is ironic is that the SP market is arguably less competitive right now than MP, allowing more chance for success if you get it right.
Japanese developers for trying to ape Western developers and ending up in the middle with expected results. Special mention for SE who seemed to almost wilfully hurt their brand and franchises with a variety of odd choices both in the West and the East. Capcom also perplexed this gen seeming to be on a mission to annoy their own customers. Also Konami for fucking up Silent Hill, one of my favourite ever franchises. Thank's Konami for thinking their must be some magic formula to keep a title mature, interesting and mysterious and non-combat centric while adding a lot of combat and explaining everything Western horror film syle - now you know better maybe we can get a proper Silent Hill soon? (to be fair downpour, if technically more solid, is a bit of a return to form but still a fair way off Silent Hill 2).
To close, I'll note that while Sony entered as gen as the most likely to win based on brand position it now seems clear that if Nintendo had just pushed a bit more power into the Wii, sorted out online and got Ps3/360 level third party support they'd have scored PS2 big this gen. Not that they weren't successful, but they could have appealed to almost everyone with a few different choices.
On a positive note though I'd say Steam, Valve and my PC did nothing wrong this gen that I could notice.
Try to be reasonable... its easier than you think...
