No, it's not the 1950s, when people were made of stronger stuff and didn't have the sense of entitlement they have today.
Remember the old-fashioned style of pram? My mother used to push me around in one and she would walk all the way to Penge and back. She didn't have the luxury of being able to get on a bus with it, and I doubt she could have navigated the subway either. I'll ask her. Although it may trigger her on the subject of modern mothers who complain that there's not enough room on buses for more than two giant buggies...
We're just talking a few weeks of inconvenience. And it's not 350m: it's the difference between the alternative (eg going through the station) and walking around the long way. As for the comparison with moving the pools, that would have been permanent, not temporary.
And if you can't handle this amount of inconvenience then just be thankful you don't use any train services that have long term disruption during improvement works. Off-peak Thameslink services have been affected for YEARS.