True there are times when things are fixed and are not reported in the release notes that players have came across.
But it's still embarrassing to them either way. Who reads patch notes? Players that come to the forums and Beth sites, these people know what bugs are in the game anyway as the community has included bug list for them to see them. It would be less embarrassing to be known as the company that fixes a lot of bugs in a patch rather than the a company that just ignores them and hopes it goes away.
Relic entertainment took that route with the Dawn of War series, in that the published details of extensive patch changes. They got heavily slated every patch because of the number of bugs listed that were corrected. This came to a head with Soulstorm where Relic was unable to patch the game AT ALL due to a major design flaw in the game and its DRM system by its contracted developer which took them over 6 months to resolve. They were flayed for months for providing patch details prior to them releasing and the patch not coming or coming with less fixes than listed originally due to tech issues.
With DoW 2 the patch notes slimmed down, none were given out early, major engine changes were lumped in to "stability" and" optimisations" headers.
Its a double edge sword with patches.
Really? Skyrim is the buggiest game I have bought in the past few years. CoD comes out in better condition, as does, Batman (both games), Prototype 2, Mass Effect 3, Gears of War 3, and pretty much ever other game made by a semi known developer.
Cod is always buggy as hell at launch, with glitchers all over the shop and hackers running around willy nilly. The other games you mentioned also had plenty of issues on release, and with previous versions of the games on various platforms. Epic even stated they would no longer make PC games and only do console titles due to the backlash from the Gears 2 problems and GFWL. Batman was pretty solid, but its based on an engine thats been heavily used across a number of developers and refined somewhat, same with Mass Effect. Refined engines make it a lot easier to develop a game with less issues initially but they still both had plenty of problems on release, Mass Effect 3 having an automatic CTD with its eden prime DLC for instance. As another example, Crysis 2 was a major multi platform game, released to much fanfare and with a huge budget. Its as buggy as hell on all 3 systems and support ended for it less than 4 months after launch.
No game is bug free. On a content per bug ratio, Skyrim aint actually that bad. Its a lot better than some bigger budget titles