The demand from these stations is tiny though - they each see a few thousand passengers annually. There is no fixed link public transport investment that could be justified for that low level of demand - it's just the wrong solution for public transport provision to these settlements. Alternative provision already exists in the form of buses, which are often more convenient than the poorly located stations.
...writes someone who has clearly never used the line and doesn't know much about its context
If you consider the stations as serving the places they're named after, perhaps that's right, but that isn't what they serve in practice. For instance Bow Brickhill would probably be better named Caldecotte & Tilbrook, Millbrook instead Marston Moretaine, Ridgmont instead Brogborough etc.
Demand is certainly low, I don't disagree, but buses are irrelevant as there basically aren't any. Indeed, the line survives, if I recall, because it was too awkward to properly serve by bus and so United Counties refused to do it. We do need to bear in mind why usage is overall low, though - a combination of the lack of a service to Milton Keynes Central and the extremely poor service offered which has been the case for years. There is no reason a station like Bow Brickhill right next to a residential area and large amount of industry should have a very low usage as such - if it was on Merseyrail, for instance, it would clearly be fairly well used. That's why I'm concentrating on that one as being the station that the consolidated plan does, but shouldn't, leave out.
The rest of the consolidation plan largely makes sense, though I think they are making the wrong decision relocating Ridgmont and using that one as the answer to Apsley Guise. Really, Apsley Guise should get a footpath and cycleway alongside the line to much nearer Woburn Sands and leave Ridgmont where it is, where it has a large potential for inbound commuting (and already carries a fair bit). The only way moving Ridgmont into the middle of a field the wrong side of the motorway actually makes sense is if an eco village was to be centred on it, but I've seen no such plan. And their statement about disrupting business really makes very little sense - the only business it would disrupt is a scrapyard and trailer yard which as I note above would be easy and cheap to relocate, the only buildings are Portakabins and the likes.
If we lived in some sort of alternate reality where the line between Woburn Sands and Bedford had closed, but the stump remained with a half hourly Mon-Sun Woburn Sands to Newport Pagnell via Milton Keynes Central service and development concentrated around Woburn Sands and Bow Brickhill I reckon it'd be as well used as any random DMU suburban service around any other medium sized city (perhaps comparable with say the Exeter local services). That isn't where we are, but in considering whether the stations are useless we need to also consider hat they wouldn't be if they had a service geared towards where locals want to go. But equally, like say Wedgwood and Barlaston (which were low-used but weren't useless either), they are effectively being closed for the greater good of pathing a better longer distance service.
On the other hand, Millbrook and Kempston Hardwick basically don't serve a purpose (the latter is getting some increased usage seemingly from people living in the new bits of Wixams, but they'll move to Wixams station when that opens), and closing those (as is effectively happening) is hard to oppose, though again I think cycle/footpath provision needs to be ensured between Lidlington and the Marston Vale Country Park as while the line isn't particularly well used for that purpose it does have the potential to be with the planned improved service. Again in the parallel world of EWR not happening and a more local-geared service through to MKC, I'd have put an ecovillage centred on each of them, but of course the theme park will now step into that role centred on the new Stewartby station basically between the two with its own internal walking and transport routes.
