Shoes are part of a rider’s clothing so don’t count to the bike weight.
But you have to accelerate them round in circles a LOT on the average ride, believe me shoe weight is a factor in racing circles (delicious pun intended)
My point is that pedals are arguably different from tyres and other components as they are more than just a preference, for example, if I ride SPDs and you ride flats, we’d have a hard time swapping bikes on a ride, but our choice of tyres or gearing wouldn’t.
Pedal choice forces you down a particular avenue, if you were looking at bike X supplied with SPDs and you’re a flat rider, comparing it against bike Y supplied with flats you’d have to start looking up pedal weights and doing mental-swapsies to compare, better that they’re just both listed without pedals for an even comparison, especially since pedals are often not supplied OEM or only basic plastic jobbies to get you home.
Pedals exist in that dodgy zone where they’re more than a preference, but still part of the bike as well as the rider, if you could imagine that all bikes simply had ‘default spindle X’ fitted to their cranks, and your shoes/pedal 9as a unit) slotted onto them then you could take them out of the equation. But as it is there is a reason why bike weights have historically been quoted without pedals.