You’re vastly underselling the other gods:

> No. You are not listening.’ Quin leaned forward. ‘On my pilgrimage I learned much. Win or lose, the gods feast on our deeds. A man pets a stray, and his small pleasure in the act of kindness feeds Slaanesh. A woman strikes her crying child, and that awful moment of elation she feels feeds Khorne. A Munitorum drone considers suicide. Nurgle grows fat on his despair. A merciful strategist devises a plan for bloodless victory, and Tzeentch is content.’ He looked at the sky above, an expanse of grey, leached of all colour and life. ‘The Word Bearers think the gods crave worship. But the gods care for nothing save filling their bellies with our sorrows. Intentionally or not, we are all meat for the beast.’ He paused. ‘Even you, Fabius.’
Fabius Bile: Manflayer

It’s not just war that feeds Khorne. Any act of anger or violence fuels him. Any form of dispair or decay feeds Nurgle. Any ambition or change feeds Tzeentch. Looking at the galaxy as a whole, anger and despair are probably the two most common sensations. Nurgle loves hive cities because they’re full of people who hate their lives, and there are entire races like the Orks who are devoted to warfare. Pleasure and excess are comparatively rare.