i think accept salary in bitcoin is best idea to hide from tax.
Unless you're from a third world country and the signature campaign payout levels with your weekly or monthly wage, you can somewhat make that comparison. But when you're not, then the only way to look at signature campaign payouts is to see it as a bonus. And nothing more.
You have a point, signature campaigns earning would be decent enough to compare the salary rate in 3rd world countries which is very useful because you won't do hardwork already because you are already earning decent in Bitcoin and it really depends on what country do you live but still remember the risk on Bitcoin because it's not stable as of now to fully rely on.
Even if you are from third world country I don't thin that only earnings from signature campaign would be sufficient for living, as payouts are too low and it can take care only of your basic expenses.
I knew some people here who made a living with just the earnings on signature campaigns which is really incredible because as i can see the amount of joining signature campaigns is just enough as a pocket money for your self but some already made a living with it especially who live in 3rd world countries which i mention earlier.
I live in third world county and my signature pays me 0.035 per week that is 0.14 per month and to be honest its not possible to survive with income of 0.14 per month.