I feel you've misinterpreted me so I'll clarify. When I refer to quality I mean that the company in question, in this case Microsoft, should take the time and effort to deliver to the masses a truly solid, reliable product that has virtually zero issues. When companies do deliver such a product, the masses are satisfied and they will fork over the money to buy this wonderful product that has made everyone around them happy to use. The money will naturally flow towards the company with a really good reputation under it's belt. In the case of quantity which seems to be all the rage now you have companies that are selling incomplete products littered with bugs and other issues and this leaves the masses angry and asking the big questions about said companies. In this case the companies start to lose money rather then making it because they sullied their reputations with shoddy workmanship, tight budgets, limited time scheduled, etc. In this scenario the quantity is all abut how much money they can rank in without caring about the quality of the product that should have been made properly the first time, and exist as the main priority over finance. Companies need money to survive, yes. In such a world as this that's the ugly truth. But it should not be at the coast of their reputations and products.
I was just using a little hyperbole, but I'm glad it's bringing up discussion.
There gets to be a point in the development cycle where you've spent too much time fixing bugs and making the damn best product you can that you will start to lose money, even after launch. So managers and the like calculate at what point do we need ship the product to even see profit and hopefully fund future fixes with the product or start development on the next version of the product. So while I understand the consumer sentiment, "Why wasn't this in development longer to fix everything?!" the answer is that it would of killed the company or product. (It's not uncommon for products to just die in development because of this)
And I don't think anyone in the industry really doesn't "care about the quality" of the product. I highly doubt that there are people who just want to release garbage (though at the same time it wouldn't surprise me if there were), so it saddens me when I see people make statements like that even though everyone is trying their best to release a stellar product. :'(
Now, with Windows specifically the development cycle is based off previous work on the released platform. Like I said earlier 2000->XP->Vista->7->8, at their core you'll find a lot of features introduced in 2000 used in the later versions of Windows (MMC comes to mind) still because their platforms were based of 2000.
So as you can imagine it doesn't take nearly as long to introduce a new version of a product if you design if based off the previously released version of the product (as opposed to building it from scratch). Not to mention, you don't let your dev team sit around collecting dust after releasing your product. You get them to work on the next one! (Granted a portion of the team is left behind to dedicate to patching the just released product when users find issues in the wild that could not be accounted for during development. Remember kids, nothing complex is 100% bug free, no matter how hard you try, you just haven't found the issues yet and someone else will).
Also, let's look at the release schedule for the past couple decade for major Windows launches.
Win 95 (95)
Win 98 (98) - 3 years
Win 2000 (2000) - 2 years
Win XP (2001) - 1 year difference
Win Vista (2007) - 6 year difference
Win 7 (2009) - 2 year difference
Win 8 (2012) - 3 year difference
We see that 2-3 year development is about the norm, the fluke being the time between XP and Vista. If we compare this to Apple and their OSX lineup (remember these are update you purchase [granted cheaper than a full Windows upgrade...]!)
Cheetah (2001)
Jaguar (2002) - 1 year
Panther (2003) - 2 years
Tiger (2005) - 2 years
Leopard (2007) - 2 years
Snow Leopard (2009) - 2 years
Lion (2011) - 2 years
Mountain Lion (2012) - 1 year
So again, 1-2 years between releases of major versions of OSX (yeah I know I skipped Puma, you didn't have to pay for it if you had Cheetah so I figured it was kind of moot) which were all based on building up on the previous version of the OS.
The point I'm trying to make is that not very many companies develop from scratch for each new product they create (especially with OSes), so building from previous code allows major revisions and updates to happen more rapidly and get a product out to consumers sooner than later.
I don't really remember the point I was trying to make, but there it is! People are always trying to make the best product they can (at least where I work we do!) and working on previously developed code that works helps. And if there's an issue with that code, you can be sure people are looking into ways of fixing it without breaking anything else (a common issue that arises when trying to fix one then, you break 10 other things!). I hope this helped to be informative?
Anyway, tl;dr: people try hard to get things done right the first time, but it can become cost prohibitive if all we focus on is 100% bug free products (which is statistically improbable the more complex a product is), so building on previous iterations of a product allows us a faster and more stable way to release new content to users. Or something like that...?