Oh dear, does this really need to be explained again? There is no way that any band with a fan base predominantly of people aged over 25 can get anywhere near to a number 1 song now that streaming counts, so even if the Smiths reformed with their best ever single, it wouldn't make the top 20. The idea that they might have a number 1 song is totally delusional (especially if you heard the quality of the music on Marr's last solo album). Far from taking the record company to task about Spent the Day's performance, Morrissey appears to understand the way things are quite clearly (even joking about the single's chart fate in his recent German show).
Now, your assertion that because very few people bothered to stream Spent the Day this means they don't like it, and the album will do worse than World Peace. You might actually be right, here, You don't know and I don't know. But World Peace sold 18,000 in its first week in the UK - if Low in High School sells fewer, you'll have been proved right and your boycott campaign can be deemed a success. If it sells more, you will look like a bit of a tit. And I can't speak for others round here but I've never bought more that one copy of an album before in my life - I don't intend to start with LIHS.