Because bounty hunters will be one of the major factor of the ICO's success that is why the bigger the budget the more bounty hunters will come.So that is why bounty allocation would be one major factor to decide these ICO's faith when it comes to advertisement to get more investors.
I thought 'bounty hunter' means a person who is doing some actions to promote the project in order to get some free coins, am I right? Like you join my TG channel and get some coins for that. In 2014 each bounty hunter got 1000 ETH for promoting Ethereum. I read this somewhere.
So, I don't see the connection between budget and bounty hunters. Bounty is a cheap (=free) way to promote your project.