Appreciate the thoughtful reply @terrybrock and apologies for the delayed response: @suitcasemama and I were blissfully off the grid for the past few weeks in western Australia so I'm just seeing this now :)
I get your point on the multiplicity effect of outsourcing applications and agree: that was part of Apple's (or at least the iPhone's) success - opening it up for developers to go in any direction they wanted and having the free market determine which applications would be successful. This was a stroke of genius.
However, I would make the distinction between core function and add-ons. The iPhone would have been a colossal flop if it didn't at least include the basics. Imagine receiving an iPhone that didn't have a clock, calendar, alarm, address book, text messaging. Many of the equivalent basics are still missing from Steemit.
And that's where I think Steemit needs to evolve and evolve quickly if it's going to survive and thrive. If a Steemit competitor surfaces that has facebook type usability it could quickly make up the comparative advantage and head start Steemit currently enjoys, relegating Steemit to Friendster status quickly.
Thanks again for the reply. It's refreshing to see some of the 'big boys' interacting with their followers. Much appreciated!