They're the ones exploiting the system.
I'm not sure what your agenda is, but the problem is definitely the companies.
If they just paid their fair share with a little bit of mild tax dodging no-one would give a fuck. But they're taking the fucking piss at the moment, generating billions in revenue and then not paying for any of the infrastructure which is supporting their business.
Suppose there are two companies with the same business model, operating in the same countries etc. One files taxes "fairly" and one minimizes its tax burden as far as the law will allow. Which one do you think is going to be in business for longer? Which one would you buy shares in?
You can get as angry as you like at the companies, or the legislators, but in the end it's the system you need to be scrutinizing.
Also this is an advantage only massive multinationals have, so again, complete nonsense as they're already past that stage.
Who implements the system? The politicians that you and I elect and the corporations buy off, right? So who's fault is it really, the people who exploit the system, the people in charge of that system, or the people who put faith in the system giving it power?
If you could get away with murder because of a loophole, would you?
Say it would make a company more profitable, killing their rivals. Do they suddenly have a legal obligation to as a company to increase their profits?
Or do you behave ethically and within the spirit of the law, regardless of the law loophole?
So why is it ok to dodge the fiscal responsibility to contribute to the societies you are operating in?