Seems like he regrets keeping Instapaper a paid app and not making it free to go after marketshare and take on Pocket. He seems to conclude he "lost" against Pocket, and now doesn't want to make the same mistake with Overcast.
I personally don't think the patronage model will go very far. I think he's doing more to make the full app free and gain marketshare, and any money made by "donations" is just bonus. If he can grow his marketshare and get a lot of users, then it looks like he's going to try to raise funds. So, this business model makes sense for now... at least until he's able to raise outside funds.
Overall, Marco seems to be insinuating that the podcast market is bigger than people think, and VC money is going to enter the space; thus, he wants to prepare for that and maximize the potential for his app and the possibility to raise funds and go really big.
It does seem that when VC funds enter a market it presents a challenge to existing indie developers who are making a living with a paid app. The VC-funded company will provide a great app (usually) for free, since they don't need a monetization stream right away. They usually are aiming to build a big audience and then monetize later.
Indie developers are then faced with a decision. How do they compete with VC funded companies? They likely are going to have to either make their app free and go head-to-head with these VC funded companies (and maybe raise money themselves to do so). Or they can narrow their scope and become more niche apps appealing to a more limited audience with high-end (hard-to-copy) features that might not appeal to the masses but to the minority who might pay.
But overall, Marco's blog post does bring up the challenges indie developers face when VC funded companies enter their space.
Would love to hear more thoughts on this.