@derszoger Which Gedolim? The Gedolim have been divided on these issues since 1948. Rav Shteinman famously said that bachurim going off the derech should join the army.
I have several opinions on the topic. First off, people living in Eretz Yisroel have to live like Israelis. That means either being Da’ati Leumi and allowing your children to join the army, or being Chareidi and letting your children sit in kollel for their entire life.
Secondly, the situation as it is now, is terrible and in serious need of change. Joining the army (even Nachal Chareidi) is not an option for most Chareidim, and sitting in kollel forever is also not an option. Something has to change, and I believe that with the exploding Chareidi voting population, change will happen to allow for more and more options other than kollel or army.