For my basic knowledge working side by side with a lot of devs, I totally agree with the way Ernest thinks. It's essential for a product that's growing up to have a solid core that will not need to be rewrote in the near future.
But also, as an user, I keep wishing we could see more features, like the API for mobile apps.
I mean, besides what Ernest and Melroy thinks that's the right way, there's also what the users need, what the users want and what the project needs to escalate (new features vs core rewriting). And probably there's not a right answer for that.