What can't I be serious about? That I upgrade when the performance difference is large enough and time is not a large factor? Give me 50% more performance and I'll upgrade. If it takes you 8 years to do it then you won't see a penny from me until that time. If you do it in 3 years then I'll upgrade then. Personally I weigh out how much more I'm getting for my dollar and for CPUs that is my threshold. Not saying you are wrong, we can all have our own personal criteria of what we think is "worth it".You can't be serious. I'd rather spend my money on a video card or nice display than shitty CPU that I put inside the box.
I treat GPUs the same way. If the best Nvidia could do in 6 years is 25% more performance I'd still use the old GPU. Also, not everyone needs a new GPU or display. I already have a three monitor display setup I'm happy with.