The difference: A father-in-law supports out of love of his children & appreciation of Torah study.
The Israeli secular court Hates Chareidim & has zero appreciation for Torah study.
The government was only supporting yeshivos for political/legal reasons & always hated the fact that Yeshivos were getting money. Chazal tells us that if you dishonorably give tzedakah to an Oni, you lose your sechar.
The Brisker Rov said that the founders of the State wished to replace Judaism with Zionist nationalism. & many Israelis still hope for that ideal.
The money was never given out of respect or appreciation to the Yeshivos. How loud would your thank you be if someone reluctantly gave you a present only for a kickback (votes) but he actually hated you?
Even if it always would have been given out of goodwill:
These tens of thousands of families already live on very low incomes, to suddenly cut funds from their basic necessities for a political reason is an act of cruelty! Tremendous achzorius!
For families with many children, the mothers work hard on low pay, to half their income suddenly is a tremendous rishus!
The court & the leftists are certainly Reshaim who deserve no thank you from the Chareidim.