By the same token, I've inherited projects where the developer did not take scalability into account and avoided "cogs" for quick development turn-around. Putting the "cogs" in afterwards was incredibly painful, and a lot of development effort could have been saved if some thought was put into the architecture.

Quips about premature optimization often make the assumption that any optimization is premature. If data or usage growth (or uptime guarantees, for that matter) is an inevitability, then its often worthwhile to have at least some plan to grow your system beyond a single machine.