Apple has posted a technical note detailing how to “Remove iTunes gift album ‘Songs of Innocence’ from your iTunes music library and purchases”.

Here’s what happened: They did not force this onto your iPhone. They credited your account with a purchase and your device was set to automatically download purchased songs.

[ADDED: For example, my iPhone is not set to automatically download purchased songs and I do not have them on my iPhone. My iMac is set to automatically download purchased songs and I do have them on my iMac.  This is a conscious choice I made because my iMac has a 1 TB hard drive and my iPhone has a paltry 16 GB. I recognize that not everyone makes these decisions with the same level of deliberation as I did. But the option was, at some point, selected by the user.]

Should they maybe have considered that people might not want this album and that musical tastes are very personal and maybe it should be opt-in and not opt-out?

Yes.

Is this just like installing malware on your device?

Please seek medical attention. You have what practitioners of 19th century medicine call “the vapors”.