I use the LGW shuttle for meetings in Brighton and find it cheaper and more convenient than a train jny all the way from Stalybridge. Last time, the 0820 was packed out with business types and I'd guess only 20 connecting to the long hauls (they had to dash and made themselves visible to crew).
Return jny also seemed to be very few 'connectors'.
I'm sure the stats have been analysed but the am/pm are used predominately for South London area business. Guess the mid day rotations are affecting the daily totals and leading to an incorrect conclusion.
Selfishly speaking, a business day rotation to/from LGW would suit me just fine
(Ironically a few of those 'business types' were easyJet management who made the most of the 'free' on board refreshments)