Why would anyone vote "NO"
It's about close as you can get to saying you don't want democracy
People die in many places to just get it and yet folks here seem to not even want electoral reform. AV was actually suggested over a century ago in this country and if they could understand then - then I don't see why not now.
Electing an MP who is preferred by over 50% of the electorate is frankly a no brainer (meaning more people want the MP than don't) - and the only fairer system is true PR.
This makes it real easy to understand
Don't let the Tories make a monkey out of you - unless of course you're already a member of the super rich - in which case it might be in your interest to keep the Tories in power