Xenia, I was still crying every day until about 6 weeks after the birth.
I had a traumatic emergency c-section, breast feeding didn't work out for us so I had the emotional trauma of getting over that,DS was waking up every 1.5 hours from midnight to seven am so I wasn't in a fit state to do much during the day, I certainly wouldn't have fitted any of my work clothes never mind putting my work brain on.
Plus I don't know about your job but I certainly don't find that mine gives me time to relax, drink loads of coffee and sit still at my desk all the time. Perhaps I am in the wrong profession.
Perhaps this was because I had DS at the relatively late age of 35, if I was younger perhaps I may have found the adjustment easier, who knows ?
These are just my personal circumstances, there may be a small percentage of the population who feel differently about it and yes why not let them go back to work. I know that childbirth is not an illness but a C-section is major surgery, would you be suggesting that women who had hysterectomies rushed back into the office, well actually you probably would if they had small children.