[rpcorb]

Why don't they have a stake in the outcome anymore?

[rwmj]

Because they won't be around for much longer, so they won't pay many taxes compared to someone aged 16.

(For the record: Devil's advocate take. I think this whole idea of voting in proportion to your monetary value is ridiculous.)

[jackvalentine]

(For the record, I also think this voting in proportion to your monetary value is ridiculous.)

I was more thinking however that their average life expectency doesn't allow for long-term consequences of elections to affect them.