Why so salty? The word PRO means NOTHING!!The Word pro todays is attached to an iPad....that should tell you something.
Yes newer HW and SW might have an advantage, but if you know your way around there's nothing you can't do with older software / hw.
Where i live, most professional printing agency still use dated software (because of the cost of newer hw) they definetly do not use PPC, but still it means it works for them, and guess what? When i bring them my files they are perfectly compatible!
The "additional" CPU is useless for most users who feel the need to upgrade because they think the newer sw will make them better, again, depending on what you do you do NOT need the additional CPU.
Getting the most of your HW and SW is what counts (and what real PRO knows how to do), I can perfectly sell my work (graphic design stuff) done with CS4 and a PPC, a newer computer would save some time yes mostly because fo automation on some softwares, is it worth to me? Definetly NO, otherwise I would have upgraded, as a matter of fact i had a 2013 MacBook Pro till last year, but sold it because it could not do anything better than my ppc (again for my needs).
Video editing you have a point, Audio...well that's a may be, graphic? If you know how to use older sw there's nothing you can't do, at a fraction of the price, and with very little time difference.
The bottom line is, use what fits your needs, do not use tags like PRO wich means nothing and do not get mad others can do stuff with older HW while you cannot.
You should learn more about what can now be done creatively with the additional CPU, and its quite valuable to any phase of writing and production.
May be you should learn what you can do with older HW, you might be impressed,I am really curiuous to see what you do with your newer computer that I can't do

....
I'll leave while I go back to mixing music in the present for the future.
Bubye.
I leave you alone while I go make some graphic design for the present with older machine.
Bubye.