This is probably true. It's slightly frustrating that the D2 & D3 are daytime only routes, as my mum lives on the Park Avenue estate and having the option of leaving the car at home when I visit would be nice... However one person occasionally using the bus isn't going to make an evening service viable. It isn't a new thing that there's no bus along that section of the A629 after 6pm anyway, you'd probably have to go back to the 1990s to find one (which possibly would have run right through to Sheffield).
Agreed, it's a long time since there were evening buses down the A629.
When I first moved to the area in 1987, it was the 235 and 236 Huddersfield - Barnsley. The 236 served Highburton and then down Busker Lane at the Windmill Inn, before turning right to Denby Dale and Cawthorne, while the 235 went direct through Kirkburton, then down Highbridge Lane and left to Clayton West and through Kexborough. Both ran hourly and were shared between Waterloo and Barnsley depots of Yorkshire Traction (Waterloo had 2 of the 3 workings on the 236, and one of the 3 on the 235, Barnsley the opposite).
Shelley and Shepley were served by the X39 to Sheffield - which later became the 234 to Penistone and then Barnsley - and the irregular 285/286 services to Upper Denby which were tendered and went through a number of operators, and went via convoluted routes to say the least.
When Yorkshire Travel introduced to 240 to Clayton West - via Lepton and Highburton, using mostly new, leased Volvo B6s, Yorkshire Traction reacted quickly, introduced a copy of the route, and brought in Darts. Similar then happened with routes to Denby Dale through Skelmanthorpe and Shepley.
The routes were overbussed, but it did prove there was a market for a better service. It also, eventually, killed off the cross-border routes to Barnsley from Huddersfield and removed the double deckers from the routes too (getting the coach seated Metrobuses from the Barnsley allocation was always a rare treat!).
The mostly rural area SE of Huddersfield has always been a relatively affluent area, with a few pockets of deprivation, and it's perhaps no accident that the latter are served better than the big, car owning estates like Shelley Park, which as others have noted was never designed for buses or through traffic.
Shelley College - in my day Shelley High - is a big traffic generator, too, with a host of local school routes and a good number who use the now D1 and the X1 to get to/from school too.
