For those wondering why Patreon went for more funding even though they should make about $7.5 million this year from the 5% fee they charge: They are growing faster than their current cash flow can handle and need to increase their staff beyond the 70+ they already employ. They are still a "young startup" where they can get this sort of funding where a standard growing business would get a loan.
There are a lot of unsatisfying answers to this question on the thread. Put another way, why does Patreon need $60M when Kickstarter grew to 134 FTEs on $10M investment? + Is it that Patreon is managed worse? + That the ecosystem has changed in the last few years? + Are they trying to do something substantively more intensive than Kickstarter?
Patreon has a slow and steady growth rate, while Kickstarter grew quite rapidly gaining a lot of press from big campaigns brining in huge amounts of money all at once(where Kickstarter got a huge influx of cash each time a 30-day campaign completed). For Patreon, people are more hesitant to sign-up for a subscription type expense. After a popular creator starts a Patreon and gets that initial boost, the growth rate for them is quite linear.
A large Patreon campaign of $60K/month nets Patreon $3,000 while a large Kickstarter campaign of $3M nets Kickstarter $150,000.