oomis:
The amount of time lost learning while they’re in the IDF is not the worst problem. The biggest problems are the IDF itself: the shmad, the arayos, etc.
As well, it’s nice that they’re “erlich” and also that (you THINK) it did not compromise their frumkeit.
But the gedolim still forbade it, then and now, as others have noted.
You also don’t mention the tragic percentage of “D”L” that come out of the IDF not dati any more.
Finally, any frustration should be directed at Israel and Zionism because the shmad that are both Zionism and Israel/IDF is the main reason why the IDF is a non-starter for any Torah-observant Jew, as per the gedolim.