The Eloi metamorphose into Morlocks.Your MOGWAI is evolving... MOGWAI becomes GREMLIN! Your PAK BREEDER is evolving too... BREEDER becomes PROTECTOR! Could the reason that there are no elderly Eloi be that those Eloi who are not eaten become Morlocks, no longer able to gain sustenance except through eating their young who retain the ability to process plant matter? It'd prefigure the Babyeaters from Three Worlds Collide.
When the Time Traveller (book version) mentioned that his earlier class struggle theory about the Eloi and the Morlocks was incorrect...
The Time Traveller wasn't human.He's actually a visitor from an advanced world, and came to Earth with one of two objectives. He either A) actually had a time machine and wanted to see if humanity was responsible enough to be trusted with it yet or B) knew what would happen to the future Earth and came to warn them. Knowing that simply dropping into the world and telling them would get him institutionalised by a society that wasn't very nice to it's mentally ill, he set up a backstory of sorts as a respectable member of society and tried to warn them once he thought he might actually be listened to.