I've always thought it was the other way around - low buy-in casino ring games (so $200-$500NL) are about as loose as poker gets. Here's why, AFAIK:
- People are only playing one table at a time and they're not seeing that many
hands per hour. So they're more inclined to play the ones they do get dealt.
- The quality of the play is usually so bad that people think any two cards can win.
- There are a lot more pure gamblers (as opposed to poker-only players) at casino tables because they can just walk away from the craps table and sit down at poker. You can't sit down at an
online poker table on a whim, you need to sign up and deposit.
- There's more drunks.
All these things = LOL loads of people playing loads of hands in live games.