Its true, Costco, Ikea and other large retailers are slowly eroding the usefulness of the bicycle in Japan as they promote a car centric approach to shopping.
Both Ikea and Costco offer home delivery, should an adventurous cyclist or user of public transport make the trek to one of their stores, but judging by the size of their car parks there is no mistake who their target market is.
To be fair I should point out that more and more often large Japanese owned shopping malls such as Aeon are popping up in all manner of sparsely populated locations essentially inaccessible by bicycle. Surely this is an aspect of western culture we should not mimic.
I sincerely hope this trend towards car centric shopping begins to fade here in Japan, before it negates the convenience of the bicycle completely.