I say only the patriarchal heads of households should get votes. Isn't that pretty much how Athens did it? No votes for slaves, women, anybody with mixed non-Athenian ancestry, no poors allowed to hold a political office...
Anyway, I'm all for putting the sons of politicians on the front line, but don't think that will stop wars. The British Empire was infamous for putting nobleborn men directly in harms way, they would proudly stand up right in the thick of combat making themselves tempting targets and were routinely cut down. In a society with a strong martial tradition this doesn't turn people into peaceniks, if anything it gets people even more excited for wars.
The Brits had this as a custom back when it was viable on the battlefield. They tried to stick to it during WW1 with quite disastrous consequences, which is why they stopped. Well, some brave souls still tried it occasionally in WW2, but any British officer who'd try to do that kind of thing today would be considered an idiot endangering his unit.
Strong martial tradition or not, whether combat is seen as desirable depends a lot on the level of personal risk for those involved. Which, by the by, is why feudal nobility was much more enthusiastic about warfare than the peasants - having good armor significantly reduced risks, and chances were good you'd get ransomed if captured.
When applied to modern warfare, it pretty much depends on whom you're fighting. If it's a modern army (in the sense of military doctrine first and foremost) against premodern one, whether the latter is guerrilla or state, and you're in the modern army, your chances of survival are pretty good - look at casualty figures for Battle of Mogadishu or Desert Storm. But if you're on the other side, the casualty rate is so high that people need some other motivation to keep fighting (ideology, religion etc); very few would fight for loot or glory under such conditions.
And judging by how things are going in Ukraine, two modern armies going at each other isn't much better. Again, hard to be excited about being blown to pieces by an FPV drone the moment you poke your head out of the camo netting.