>completely ignores troves of older hardware existing in people's homes that has to run browsers just as well.
The performance has gotten worse for users of a computer from 2006, but it has improved for users of ten-year old computers (since a ten-year old computer in 2012 would have been from 2002). If you assume that a computer is less likely to be used the older it gets (and that this rate is roughly stable), then I am not ignoring older hardware at all.
>although I guess it depends on the timescale and your willingness to fudge the graph to sparse data points
thus is the nature of all real-live long-term trends. If you pick a sufficiently small timeframe, they never work.
I'm saying that the performance of today's firefox on 2006 hardware is better than the performance of 2012's firefox on 2002 hardware. I consider that to be a better measure than to compare both releases on 2006 hardware.
The performance has gotten worse for users of a computer from 2006, but it has improved for users of ten-year old computers (since a ten-year old computer in 2012 would have been from 2002). If you assume that a computer is less likely to be used the older it gets (and that this rate is roughly stable), then I am not ignoring older hardware at all.
>although I guess it depends on the timescale and your willingness to fudge the graph to sparse data points
thus is the nature of all real-live long-term trends. If you pick a sufficiently small timeframe, they never work.