I think the 7-day a week issue is very valid.
Also, if BA were to directly compete with QR on the LHR-DOH segment they would open themselves up to a yield conflict, and QR's yields are renowned for being absurdly low.
Personally, I'd rather there were two seperate flights. Bahrain is so busy now due to the growing economy, lack of competition from GF and also Dharhan traffic it's a nightmare getting a seat during the busy periods!