How Did Rabbi Akiva's Students Die?

Why is the mourning period for the students of R. Akiva, so much more halachically serious than similar tragedies, in Jewish history? The class deals with the historic background of the time, as seen in the sources and archeology, which explicitly prove that the tannaim, R. Akiva's students, learned in a "Hesder" Yeshiva, combining Torah study with army service. They didn't wait passively for the redemption, but actively tried bringing it in the religious-Zionist way, which in their time was premature, but nevertheless serves as the Rambam's precedent for the future geula. Many other "innocent" sources in the Talmud are explained here, on the backdrop of the historic events of their time, and show that the Omer period mourns the fall of the 3rd State of Israel, a true national tragedy.