Did you read the article? She wants to obtain British citizenship. To do so, she must first obtain a document certifying that she has a right to live in the UK. That is a requirement for any EU citizen who wants to apply for citizenship. How is that meaningless?
As an EU citizen, she has the right to live in the UK, currently. Applying for permanent residency would be approximately like me, as a US citizen, applying for permanent residency in the US.
With Brexit, in the future, that won't be the case. But until the UK government, in negotiations with the EU, determines how that is going to work for current EU residents, there's no point in dealing with an application process that is not meant for her situation.