"useless" is more extreme than "sucks". I think it is dismissive in the same way as describing something as "FAIL". People are being exposed to more options and are being asked to make more and more judgements. I think making a gray analysis like "It's good at this but bad at that" is hard to keep track of with the quantity of options. It is far easier to simply lump things into black and white buckets of good and useless.
But ultimately what's "useless" is the comment itself. It does nothing to better anything. It leaves the developer in a void of wonderment. What's useless? Is it lacking a feature? Is it not working at all? What void were you looking to fill?
I also get an overwhelming amount of 5 star ratings with well thought out reviews. So when one of these "useless" comments pops in, it throws me back to high school days, when everything "sucked" - which is why I wonder if the word is the new "sucks".
Thinking back, saying "sucks" so often was quite useless.
I don't think the 1-star reviewer is thinking of "you" (the developers), at all. They want to bury the app so that no other user will have to waste their time in the same way they just did. It "sucks" but I don't know how you could change it.
I'm wondering if this is a new word among young people now. Kind-of the new "sucks" maybe?