Why not? It is way simpler to write and requires no infrastructure to hold and release keys, etc. If you are crook who would create ransomware you don't have any honour anyway. Of course if this gets more popular, fewer people will be inclined to pay anything since chances of getting files back won't look so good, but criminals are in it for quick buck anyway.
The problem is not with users being lazy or stupid as it is suggested in the article, but with TOS.
For example Apple's TOS is 56 pages long and reading it won't you much good since without lawyer translating from legalese to English you are probably going to miss quite a lot of legal traps anyway.
The 'fix' is to stop treating TOS as if it was a law - at best it is a list of company's wishes and hopes.
I am sure banks will be leaning on May very hard to get a deal that includes passporting. And since financial services are huge part of British economy, they are likely to get it even if it requires huge concessions.
Rather ironic that this kind of article would be published in Guardian, considering that it is pretty much a progressive echo chamber that has no trouble to distort the truth whenever it is needed to push a narrative.