Writing in present tense is the Hot Thing in YA, Allah only knows why. It makes my teeth itch.
This thread is probably full of a lot of writers but my take is that it's generally easier to write and a cheap way to make a scene more engaging for adult dopes and child weirdos.
Like telling a campfire story and making people feel they are there actually in the moment, it's just saying "picture THIS" so you can have looser sentence structure and people will be more forgiving of the wretched prose. A lot of teens and child writing enthusiasts default to this, and some as they grow older may use that as a first draft tactic to block in the general flow and plot progression, but to just publish what seems like a really hacky first take should be more insulting to people that it seems.
Also, this has been covered, but the main driving force for these people is the opposite of someone like Tolkien or Joyce who might dedicate huge amounts of time in pursuit of one great work. These people love just being known as authors. So to them, they're having fun doing what they like as a corporate gig. These are glorified Powerpoint presentations but they see themselves in the same league as Frank Herbert.