Why are people okay with losing if you lose a teamfight near inhib 25 minutes in?

Or at least coming god damn close if your death timers aren't too far off. It just seems obsurd that people can confidently say ggg at a 25 minute inhib ace in Rift but not ARAM ( to my recent knowledge). Like seriously why are people okay with this??? It isn't even fun regardless of what side you are on. the damage surprises me every time when I've got an ADC and 2 other champions that can siege the inner base in like 25-30 seconds or at the vary least most of it.