Earlier quoted context omitted.
These companies evading taxes are responsible for increased hardship and suffering of a society as well, leeching off of the nations they exist in, and being able to outcompete the honest organizations and people in them. The damages are far greater than the tax avoided. "They are doing it too" isn't a valid excuse either.
They aren't, for the most part, doing anything illegal though. They are using the existing laws to their best advantage. The fix for this can't be trying to appeal to their morals. It would have to be something else that just limits the legal choices. Edit: If you disagree, are you saying that shaming them into not doing this solely on some moral compass is the right fix? Does that scale?
Some of these accounting and financial advisory companies are also large campaign contributers with revolving doors with relevant government departments.
There is an inevitability about it, but many are either on koolaid or demonstrate an intentional naivete.