Pete - you got most of it but missed some.
After you start donating your time (valuable things) to become a beloved pioneer, eating Raman noodles and pbj sandwiches, paying for your own fuel, all while working a part time job because higher education is demonic, you have to be guilted into donating your first fruits (the best, and potentially all you have) because the work is speeding up so much and the wise slave class doesn't know how to get by.
And, remember, the GB is not soliciting. They are merely making the rank and file (aka the ones with jobs and income) AWARE of the non-statistically supported statements that their is this huge need for funds.