Can't really be surprised by the axe when there's not really any story to speak of. You could easily re-order these chapters and no one would notice
Newspaper comics also don't have plot progression. That wouldn't be enough to kill interest.
If it's not that it was already determined that this would be a two-volumes-worth serialization, then-- under normal circumstances-- the tankoubon didn't sell well enough and the publisher didn't want to continue its investment in the work.
Or, the mangaka themselves didn't want to continue.
Fcking Japan, kills the good stuff and let's shit like Rent-a-Girlfriend thrive
Sometimes I think some of the people that use that manga as a punching bag are secretly buying the tankoubons (furthering its success in the process), like Squidward in that one episode when he wanted to hide the fact that he liked Krabby Patties.
I don't even hate it at all (it just bored me enough, and it has the pacing of a long-running action shounen), and I talk about it less.