There are at least two interconnected issues here. The first issue, is that the words 'how' and 'why' have a habit of being used interchangeably, and not only in everyday, colloquial speech. I suspect the word 'why' crops up in a good few scientific papers as well. The second issue, is that in scientific circles, 'why' is frequently a shorthand for 'what processes model the data?', whilst in supernaturalist circles, 'why' is pressed into apologetic service to mean 'what does my magic man want us to do, and what can I make up about the data to try and enforce this?'
This is why Nietzsche was so scathing about a good number of contemporary "philosophers", who erected metaphysical assertions not because they were actually interested in elucidating the structure of reality, but to press those assertions into service as a device for imposing an ethic upon the universe and its contents, regardless of whether said universe and its contents actually agreed with this, in order to make it easier to impose that ethic upon other human beings. Supernaturalists haven't been the only people to adopt this tactic, of course, but they've been amongst the most enthusiastic applicants thereof, because they learned quickly how attempts to ascribe to their ethical assertions, a status akin to that of physical law, were useful with regard to imposing said ethical assertions upon others.
Of course, the huge problem that this process faces, is that any ethical assertions that did possess a status akin to that of physical law, would not need other human beings to enforce them, just as gravity doesn't need us to police the non-existent tendency of human beings to float in mid-air. The mere fact that those ethical assertions do need human enforcers, tells us much about the likely status thereof as purported intrinsic parts of the fabric of the universe. Pedlars of the requisite apologetics hope no one will notice this, of course, and also hope that no one will notice the manner in which ethical assertions actually possessing said status drive an entire tank division through the concept of free will, but many here will already be familiar with other instances of supernaturalists trying to have their metaphysical/ethical cake and eat it simultaneously.