Riva:
The only downside will be you cannot describe your problem in the subject header so people will eventually get bored of clicking every "Hi, this is my first Thread" and few if any people will bother reading there new posts after a time.
Many of them have crap titles anyway. Having an enforced title may actually make them think about the usefulness of titles.
Until they adjust the robots to send the first magic post
I am assuming the title is important to someone trying to advertise something or trying to get you to click some dodgy link.
...R