Amazing how such a simple question generates so many opinions.
Having suffered bent pins on a CF card reader made me rather wary of handling cards. Not so much of an issue for SD cards but there's still a chance to get dirt, hairs etc into the gubbins. The guys and gals who benefit most from using card readers may be those with a lot of data to transfer. For them a fast card reader may be a time saver. For me a USB cable transfer direct from the camera is good enough.
In principle formatting can shorten a card's life life but let's put in some numbers. A very
conservative number may be that each cell is rated for 10,000 write cycles. So if a cell is written once a day then you'd expect it to fail after about 27 years! OK, failure won't occur at exactly 27 years and may occur sooner but just to get a sense of the scale of the problem, or non-problem as it turns out, the rough and ready calculation above helps clear the fog I hope.
That said, I don't understand the need to format the card so often. Just deleting the images on the card from the camera's menu (or even via the computer if a card reader is in use) is quite sufficient IMHO. Formatting every day isn't going to do much good on the performance side and will take more time so, if you think formatting will help, why not do it every week or every month?