I think it's more a case of a lot of the 'core' team devs also need to work in order to, you know, feed themselves and pay bills etc. So work on Monero has to fit around that. If they had more donations, they could spend more time focusing on Monero or pay other developers to work on details whilst they coordinate the effort. Unless you think they should just work for free/pay developers out of their own pockets because they owe it to you somehow?
This is what happens with a 'fair launch' where the developer hasn't pre/insta-mined a lot of the coin themselves. The only Monero they will have is from their own mining endeavours and any donations they receive, so they're not sitting on a mountain of coin they can sell fund development.