This manga wasn't axed. It's just that there is no way to end this manga with an actual conclusion. The real ending was when Hachiken &co graduated from high school. The last few chapters are basically the epilogues to show that their lives still continue on as adults, while also showing how everyone's dreams end in success or failure (or still ongoing struggle). Continuing beyond this point would just drag on the story with real world situations for the youngsters outside of the convenient (for storytelling) confines of the school.