Green isn't hot anymore? Ach, du lieber!
Getting back on point .... at some point you just have to let 'professional judgement' kick in and do the best you can. It's not that hard- as long as there's no 'disinterested third parties' involved. Good grief, it's awful easy to be a zealot when it's not coming out of your pocket! How often, these past few years, have we heard that bit of illogic that starts with 'if it saves one life ....?'
If Granny is living happily with a 30-amp service and fuses, leave it be. If she's got pennies in the holders and multiple wires crammed under the screws, then you have a problem to address. Insulation flaking off the wires? Gee, maybe the single 60watt (rated) fixture isn't enough- even if the code still says it is!
I've made the argument many times that every time we 'raise the bar' we shut more of the poor out of improved housing. We make the leap from where they are to where we want them to be a bit longer with each code change- making it certain that more won't be able to make the leap, and will remain in depression-era shacks. Personally, I'd consider a 50's bungalow or a 60's tract home to be a vast improvement ... but, no, we want the folks to go straight to a 2011 "green" wonder-hut.
Well outside the scope of this forum -but still exercising a direct effect on our trade- is also the simple fact that the folks living in these older homes often have no say in improvement choices. Their furnace isn't upgraded simply because the landlord owns it, while the tenant pays the fuel bill. Not enough receptacles in the kitchen? Well, you have too much junk. No GFCI in the bathroom? Well, don't do your hair there. Upgrade? Why? I don't live there- my tenants do.
Technically, the issue isn't one of changing the NEC. All of those who have made snippy remarks about 'it's the law' and such ought to be ashamed of yourselves. You, of all people, ought to be able to explain that the issue is one of administration (ICC, rather than NEC), and is an issue directly addressed by your own local codes. I haven't met a government employee yet who doesn't know all the intricacies of the 'system,' and who doesn't regularly tweak the system to get the answers he wants. How else do you think Chicago still hasn't discovered Romex?
On the flip side, we have many examples of government refusing to follow the rules, and ignoring those who 'get involved.' That they can do this is simply scandalous- but it's a fact. (Examples? Ask Gary, In., about CCW's, or Houston, Tx., about traffic cameras). Small wonder the average 'Joe' simply sits back and fumes.
All you creative 'public servants' out there need to get your heads out of the sand. Recognize that we have created barriers, and find ways to remove them. If it's "safety" we are to focus on, we have to recognize that there are different levels of safety, and not insist on 'only the best.'