Yep. Extremely disappointing end to an otherwise great show. After all the poignant moments and emotional highs of early episodes, "and then things were just normal and ok, there was some further character growth in montage form, and Kano and Mahiru's obsession with one another fizzled out without ever actually being addressed" was an extremely flat ending.
Another win for cynicism and never daring to expect anything good from an anime series, no matter how promising it may look to begin with.