True. But the question was "Why would anyone ..."

Actually, if one were starting from BHX and wanting to fly, there is the following choice of weekday flights on BA to CDG - 0630, 0840, 1410, 1630, 1745 - and a similar selection back again. Out at 1410 on Fri 11 April and back at 0920 on Mon 14 April scores a fare of GBP 47.90 + 34.00 = 81.90. AF flies the route, too. Not forgetting that when MyTravel Lite organised that publicity stunt a few weeks back, sending pax on AF, BA and itself to see who could get to the Arc de Triomphe fastest, BA and AF turned out to be faster - and the pax claimed to have paid lower fares than on MyTravel.