Are you also any less a supporter of hybrid cars? Electric cars (such as the Tesla)?
This isn't Segway's "fault" (except the price) and shouldn't be a surprise to anyone... at least, anyone who's owned a battery-operated appliance in the last few years. No reason to become inDIGNANt! (har!)
Even "old style" Ni-Cd cells will suffer in this sort of situation. Rechargeable batteries need exercise and cannot be stored discharged.

If you want the Segway, you'll have to pay at least some amount to re-power it. But beware of cheap replacements- half the price could mean less-than-half the battery quality, not to mention the warranty.

It's very nice to hear that your father's life was enhanced by the Segway. That's a very charming story and I'm sure the original cost was more than offset by his increased mobility. Belated condolences.