Thanks guys. My activity graphs does show a minimum number of pages crawled per day, so I guess I just assumed the home page would be one of them. It didn't occur to me that the home page might be skipped.
WMT is about 6 days out of date at the present time on one of my test domains - how do I know? Every page title tag has a timestamp visible on the face of Google so that I know to the nearest second when Google took the page. My visible homepage is 6 days fresher than the WMT message.
Answer to your question is a simple no! WMT data is inaccurate and out of date 100% of the time BUT assimilating trend movements can be useful.
I have seen the "Home Page Last Accessed On [Date 10 Days Ago]" message several times, and it has been updated several times since then, but always to a new date that is still ten days ago at the time of the updated message appearing.
The Google cache of my home page is also 10 days old, so the bot is on my site every day but not on the home page. I've been monitoring the Google cache of some of my pages. It appears that the bot is indexing my new content every day or two, but existing pages every 10 days - which, of course, makes perfect sense and I should have thought of it before.