Why do you think so? Not all sites are created equal. And Pinboard is definitely on the lean side.
Try hosting a cluster of Magento 'daily deal' sites on Amazon infrastructure, with shared storage and isolated RDS instances for each region. You end up with 15-20k $ per month for god damned bloated magento installs.
If the hosting costs are high because of inefficient software, or bad architecture decisions, then those should be changed.
If anyone here believes this, make your best estimate as to how many man-months you need for a re-architecture and how many hundreds of dollars you'll save in hosting costs, then do the division to get your effective hourly rate. I'll pay you that plus 50% for contract programming work.
In the example, the current hosting is $24k/yr.
If that can be slashed to $2.4k/yr, you've saved $21.6k a year in hosting.
For $21.6k/yr I'd say it's worth a week or two re-architecting.
Yes, it's a different game if you're profitable and $21.6k is negligible, but if you're a startup you should be spending time to optimize things.
The other point is one of scaling. If you're paying $2k/mo to support 15k users, when you scale to 15m users, you could be paying $2m/mo unless you fix things early on.
Try hosting a cluster of Magento 'daily deal' sites on Amazon infrastructure, with shared storage and isolated RDS instances for each region. You end up with 15-20k $ per month for god damned bloated magento installs.