In any case, you're talking about something different. The pictures/files have to be somewhere. They may as well be in a logical place/order. Then you can muck around with them in Lightroom/Picasa to your heart's content.
Why replicate your work ? Lightroom will create dated folders and dated files on your hard drive for you during import, you can customise the naming convention to your hearts content !
Capn Bloggs, you're just being argumentative for argumentative sake, I think you know very well that the query and filtering functionality built into products such as Lightroom beats your simplistic filing system hands down any day !
All you are doing is backtracking by suddenly trying to say I'm talking about something different. You know full well that I'm not.
As if you need an example :
You sit infront of your collection of thousands of images sorted into your little dated folders. Let's say I ask you to find me your strongest images of, let's say landscape photographs. You are not allowed to use anything else other than your neatly organised filing system... no cheating by hopping into Picassa or Lightroom - because you would only be reinforcing my point about why you need software like that !
On Lightroom I would be done before you even started as I have a "smart collection folder" that automatically queries my database for landscape photographs ranked higher than 3 stars. All I would need to do is to click on that "smart folder" in the list to bring up the list of thumbnails and I would be done.
Then let's say I asked you to look for stuff based on a larger combination of more complex parameters (e.g. keywords, image EXIF metadata, time of day, location etc. etc. ).... you would be completely lost with your files and folders ! On the other hand, even if I didn't have a defined "smart folder", it would only take me a few seconds to get the results.
So as I said. There is a reason professionals use robust cataloguing software such as Lightroom and there is no reason amateurs or semi-pros should not do so either.