Right, but you're still investing time in doing that switch. No matter which way you cut it, you're still replacing every single nail.

"We'll just update as we go", you say. That's fine, but it means that some parts of the house – normally the oldest and most integral to the entire structure - will use nails for years to come. And your developers will need to be trained in both hammers and screwdrivers to be able to work on the house in totality.

Sure, but if those nails are also causing structural instability, then it might be prudent to do the investment. It seems now, no one will be using your type of nail anymore either, so now you have to have them custom made at expense.

Sometimes those nails are doing just the opposite, they're holding the foundation together, and if you try and pull them all out the whole thing might collapse.

This is why I use Krazy Glue for everything, so I don't have to think about what's the nail, the screw and the hammer in this long-winded analogy about PHP and its shortcomings.