Yet so many visitors are happy to wait in line for over an hour for lunch at places such as Gyukatsu Motomura in Ueno - go figure.

My post was directed at someone willing to make the 1hr30m trip to Ashikaga. A trip to the Ghibli Museum in Mitaka is already on lots of visitor’s itineraries and Tachikawa is just 20 minutes or so along by train. Forgetting Ghibli, I’d recommend stopping off at Kichijōji on the way back from Showa Kinen Koen.

That for visitors there is a psychological barrier to getting out to Tachikawa but not to making their way through Shibuya Station and up to the top of the Hikarie or Scramble Square Buildings works completely in my favour. Especially as I know that many of those who go up those buildings will still need to wait around for half an hour before they can get their lunch or gain admission to whatever it is that they are there for.

ETA
Just looked at journey times for myself (I would remember 1hr20m journeys travelling with a 4 year old). From Shinjuku there are trains that take 30minutes to Tachikawa Station, from there to the Park’s pleasant outer gardens it’s a 5 minute walk.
To avoid the 10 minute walk from Tachikawa Station to Midori Bridge (which is around where the main park begins) the journey from Shinjuku to Tachikawa-Kita Station is about 40mins. There’s a park side entrance right by the station We use this for our return trip as we rather like experiencing the park’s grand entrance.

A Google map direction search for Showa Kinen Park adds walking time to the very centre of the park. That’s like asking for a journey time to a restaurant and having the time it takes to order and eat half of your meal being included in the estimate.