Win 7 is actually really stable. Really, all the NT based MS OSes (2k,XP,Vista,7,8,10) are stable. It's my second favorite OS ever behind Win2k.
Overal in relative comparison to 9x, yes. But that doesn't change the fact that XP out of the box in 2002 and Windows Seven in 2009/2010 (full disclosure I got mine in Jan 2012, but it was unoppened 2009 production), both loved to shower you with the BSODs.
My Windows Seven machine is getting better, hence my point. With updates and patches, it is getting better. However, therein lies the point. Seven is already in its extended support phase with mainstream support having ended. It probably should get another SP, but it probably won't now, not with them peddling 10.
You might have just had some bad luck (or bad hardware), 7 ran good for most people from word go (Vista did had some early problems though).
But I do agree with your larger point. The most stable OSes are the older ones that have been patched to hell and back and MS loves to stop supporting the old, stable ones so they can sell you a knew one that might have cool new toys, but isn't as stable (and doesn't feel "right") as the old one.