As to why it's important for them to attend conferences: They were founded by a domainer and receive a chunk of their funding by auctioning domains which are donated by domainers.
With all due respect - Something just doesn't pass the 'smell test' for me.
If grassroots.org receives a chunk of their funding by auctioning domains which were donated by domainers, and is the impetus for needing freebie entries into domaining events (to auction domains)...
Why don't they just use the profits from previous sales to fund entry into future events which will garner them greater sums of returns than any menial costs associated said entry fee? (Assuming they have successfully sold domains before; ...and if they haven't - like anyone, a good strategy, imo, would be to crawl before you try to walk, and learn to walk before trying to run. That is to say, if they can't afford high-cost efforts, why not leverage the free/low-cost channels which are available? - like other upstarts do in successfully expanding their coffers and continuing to grow competent businesses for the short, medium and long-run.)
I appreciate 'non-profits' trying to play in the 'for-profit' market, but again, something smells 'fishy' with the above rationale (which is not to preclude there aren't more details to this than what meets the eye).
By all means, enlighten my ignorance and offer any insights you may have into the above, as I look forward to hearing back from anyone and wish them the Best Success in All Their Endeavours.
PS: Please don't get me wrong - I enjoy freebies as much as the next person, for or against profit.