Scott, Well not everyone (as I know several).
The one really neat advantage to using any point and shoot, is it's flexibility...
I would guess you know this, but for anyone else:
"Macro" for any point and shoot camera varies a lot, not just in how close, but in how it is implimented.
Canon S95, for example, has a couple of issues that may require one to use add on lens (while a Pany LX5 will need one a lot more):
1. The macro setting allows you to focus closer, but only has a big effect if you are using the camera around 28mm. Obviously the lack of working distance at 28mm (equiv) is a major issue.
2. Zoomed out gives you working distance, but you loose most of the macro....
Still it is not a terrible camera in that regard.
A Panasonic LX5, can focus much closer (at 24mm)....so close that something can be against the glass of a UW case and it will still focus. however, as you zoom out, it ends up much worse than the S95.
Odder still, is that the LX5 goes to roughly 1 ft from 50 mm to 90 mm equiv.. so 90 is actually more magnification than 50mm...
By comparison, the stock 14 -42mm panasonic lens for their 4/3rd (what I happen to have within hands reach) actually has better magification than the LX5 (at maximum zoom and macro) and just a tiny bit better than the S95, and it does not call itself a macro lens.
Around here, most of the small stuff is 1 to 3 inches in size, so a S95 works reasonably well, without an add on lens...a LX5 does not.
I think most people believe that the "macro" setting on a Point and shoot, actually means something special over a stock, everyday lens..and it does, just not when the camera is zoomed out.
I cannot find any underwater site, that points out that an LX5 sucks for macro images underwater, without an extra lens, while other camera's work better.
Note: For those that don't know, SLR lens usually have the same focus distance throughout their zoom range, so maximum magnification is normally at the lens' maximum zoom.
Given the sensor size, the lens design could be like a small sensor point and shoot (max magnification wide open) or like an SLR, or something totally different.
If it is like the LX5, then I would suggest that getting a GX1 (or maybe one of the NEX) would be more cost effective. Camera would cost very similar (for the GX1) and the case would be roughly the same price...however, if the Sony has a bigger macro range, with it's slightly bigger zoom range (over the stock lens for those camera's) and bigger sensor, it may better overall value.
So, how close does it focus at maximum zoom, or do I have to go to a store and do it myself?
This is a moot point with a macro lens, the macro lens will allow you focus quite close. And almost every underwater photography I know end up getting a wet or dry macro lens, for good reason.

- Scott