Edit: to those downvoting this (and all of my other comments) - this comment contains only facts. So please show me where it says that there are circumstances under which they must fine you less than the maximum. Otherwise there is nothing to downvote.
Each supervisory authority shall ensure that the imposition of administrative fines pursuant to this Article in respect of infringements of this Regulation referred to in paragraphs 4, 5 and 6 shall in each individual case be effective, proportionate and dissuasive.
Note: proportionate
In the EU you tend to trust your bureaucrats to make a "Fair and Just" application of the law
In the US we tend to expect our bureaucrats to be vindictive, corrupt, petty, and generally impose fines and penalties not based on the law but based on their personal feelings about the target of their "legal action"
Thus such open ended wording like you posted being classified as a "rule" scares the shit out of most Americans
And the differences in the legal systems specifically. I think this is why a lot of HN commentators are finding the GDPR vague. In the US rule based regulations are the norm. For better or worse this tends to allow those with clever lawyers to search for loopholes. UK law is much more principle-based, which means trying to abuse the exact wording is not going to save you from a fine, and equally a technical-breach of wording is not going to get you prosecuted. It's not just the civil servants that we trust with this, it is the judges too.
The big number max fines in GDPR are there to deal with companies like Google and Facebook who can write of $5m as a rounding error.
People who have been fined at all under the existing DPA, being enforced by the very same people as GDPR, have been negligent, repeat offenders. I don't believe anyone has ever received the maximum fine in the existing regulations. That just isn't how UK law works
These rules look at whether your company has infringed before, whether you've notified the state on your own, etc. pp.
The current Information Commissioner Office system has a similar system in place. Out of 17,300 cases reported in 2017, 16 resulted in a fine. Source: https://www.infosecurity-magazine.com/opinions/gdpr-timebomb...