I think you are absolutely within your rights to raise an eyebrow. It's a peurile excuse. Do ANY buildings in this country, or anywhere else for that matter that are three - or even two - storeys high that have a lift refuse to let you use that lift on the way up, just in case you can't then use...
Only so many seats available for you to change TO though, unless the club are going so start arm-twisting people in seats with easier access to change with you. It's a bit of a sticking plaster solution though. It's a pig of a climb up those steps. With an ageing WSU population, the club needs...