The best answer is
1) He wanted to preserve Britain's trading relationship with Germany
2) He believed treating Germany harshly would lead to future conflicts.
David Lloyd George was a wise negotiator and pragmatic but moral guy. He saw great risk of future war and moral issue with drawing up too large a reparations bill for Germany, but also recognized that the British people wanted a sense of justice. He toed the line on this issue.
DLG also wanted to ensure its naval supremacy, especially in the region, but did not share the French leader's desire to complete dismantlement of the German armed forces.
DLG's main objectives were:
-steep but not crippling reparations from Germany,
-to deepen the UK's trade networks, maintaining trade relations with Germany and strengthening its dominions, like India and Canada
-to ensure its military, especially its navy, was an unthreatened force in the world.
To a large extent, he came away from the Paris Peace Conference pretty successful in these goals
