Yes, the distance from Kirkdale to GP is not dissimilar to Sandhills, but the point is, at present this only serves a very small percentage of our matchgoers with the walk putting off most of those coming from town/south Liverpool/wirral line who prefer to get off at sandhills for the soccerbus, and even combined are still relatively low numbers overall. Of course, they at least help GPs dispersal rates by taking thousands of vehicles off the road, but nowhere near the proportions we're talking about at BMD.
At the destination Kirkby inquiry it was explained by merseytravel that there was very little flexibility to add lots of additional services in terms of adding buses and trains and that private companies incur a subsidised cost factor and have historically had little natural business case take up. Which is why soccerbus consists of just a handful of buses which is barely adequate for current post match useage on those services.... so any increased provision for this site would probably be best served by extending a proportion of existing services from the South end/eastern corridors via a looped route using say Great Howard St, Boundary St, Scotland Rd (although these will have to be time-allowed within current scheduling to be viable), with some Northern Liverpool services being redirected doing the reverse route into town possibly being less time constrainedbeing more direct. However, I haven't seen mention of this, or it being being modelled (apart from vague references to some shuttle buses), so I'm not sure if existing traffic flows and junctions would allow this to work effectively using the relatively few routes available.
I mentioned the walk from Lime St because it was mentioned by a previous poster, and illustrates the perhaps slightly false perception of distance to BMD from the city centre's national rail hub. He asked about taxies and walking times etc. I said that if he was currently inclined to use a taxi from Lime St, then he probably would here too, as the difference in distance was probably as little as 10%, but with far less alternative routes and traffic lanes.
As you say, he could also choose to jump on the wirral line, change at James St and get a train one stop to Moorfields to still have a 1.5 mile walk or change again on to the northern line to Sandhills for the shorter walk. (Although he could do that directly via a change at central)
Yes, we probably all know people who walk fairly large distances to GP, but you can't plan transport logistics based on those extremes when we are looking at the relative convenience of moving large numbers in relatively small windows. A small core of our fanbase will travel to all corners of the globe to watch us, but that isn't a case for putting the stadium "anywhere".
As I said, i haven't fully read the latest revision so maybe there is greater clarity, but upto the earlier version, it looked like there will be a far greater onus placed on "Shank's pony", at least until a lot of new infrastructure is in place.... and whether or not the site and Liverpool water yields its own dedicated mass public transport network is also yet to be seen. I've heard mention of monorails and even an elevated rail from Brunswick dock to sandhills and other merseyrail extensions to open it all up, but all that will probably require far greater take up of plots than we have seen thus far.