On the contrary, it looks like the majority of the reads were classified at species level... the only problem is that the species label in your reference database is "s__unidentified". This is not something that the taxonomy classifier is doing... this is an issue with how taxa are labeled in your reference database.
This topic has a number of links that might be useful to help you understand the difference between unclassified reads and ambiguous labels in a reference database, and maybe some guidance for troubleshooting this issue:
Good luck!