Of course. GWR▸ quite rightly made a business decision, based on the serious amount of trains calling at Reading, to accommodate those beyond. It appears they thought that everybody in between the two points would be happy with the slow service, frequency and capacity over speed, when that is clearly not the case.
The problem has been around since - at least - the introduction of the
HSTs▸ , namely that Paddington to Reading non-stop is sufficiently short to make standing preferable to a seat on a stopper.
We have a similar - though obviously on a much smaller scale - problem on Birmingham New Street to Worcester (and beyond) trains in the evening peak. Completion of the Lickey electrification means that Bromsgrove has three Cross-City trains an hour from Birmingham, but the 1720, 1750 and 1759 Hereford/Shrub Hill trains continue to stop at Bromsgrove. And guess what? A lot of the time passengers for Droitwich and beyond don’t get a seat until after Bromsgrove.