No, it's VERY explicable. It's called "klintonization". The FBI was reconfigured to watch "gun traffickers" and the "religious right", because klinton proclaimed those two groups to be the only real threat to the country.
The proof of klintonization is the agency's actions after these screwups were discovered. Lose the documents, persecute the whistleblowers, and promote the screwups. That was the klinton SOP, and it has spread through all levels and agencies of the government.
Only to a point. The corruption and coverup at the Boston FBI office long predates Clinton. It is an institutional problem made worse in the Clinton years.