Do you blame car manufacturers for designing and producing new cars every 3 years or so?
Don't forget we are a consumer society and it is us consumers who drive the development of computers and mobiles and tablets and such. We always want faster, more capacity, better graphics.
Sorry but it is progress and while some of us would rather slow that down at times, the majority is against us.
As to your Win 2K system, my own XP is now 10 years old and although I use it much less than I used to since getting a new computer, it still runs fast and smooth, despite there being little to no support for it now.