Non-profits dont need to balance their expenses with revenue. They can maximize revenue, minimize expenses, and grow an ever larger bank account. What they cant do is turn that bank account over to past donors.
Large non-profits can amass huge amounts of cash, stocks, and other assets. Non-profit hospitals, universities, and special interest orgs can have billions of dollars in reserve.
There is nothing wrong with indirectly benefiting the donors. Cancer patients benefit from donating to cancer research. Hospital donors benefit from being patients. University donors can benefit from hiring graduates.
The distinction is that the non-profit does not pay donors cash.