New Creative Tools on Instagram

We can get decent prints up to about 8x8" but that's about it.

While you may want larger images, the fact is that Instagram has a large number of users in foreign markets and they're trying to expand their presence there. Increased resolution means larger resource requirements, and ultimately, a slower/reduced experience for the users they're trying to reach.

To be honest, a community like 500px might be more along the lines of what you're looking for.