Most importantly they have one bag per caddie instead of this two bag crap many places do now under which circumstance I will NEVER hire a caddie.
Really? You would rather ride than suffer the inconvenience of a two bag caddy (or do you just carry your own)?
My experience is if you want to support a legitimate caddy program, then you either need extremely wealthy customers, who do not mind paying a very high price per bag, or you need to allow the caddies to take two bags. The ability to get "paid double" is what keeps most of the caddies interested in the job. It allows the player to pay a reasonable rate while still getting the caddy an acceptable daily wage.
Most courses have a hard time keeping enough caddies around for the players who might want them, while still getting two loops in for any one caddy. So, most of them only have one round per day and $40 or $50 is not enough to keep them out there day after day. $80 or $100 is and so you either have to charge that for one bag (which most people won't pay) or let them carry double.
I have found that two bags works fine and I would rather deal with that and have a healthy caddy program, then insist on singles and find it failing.
The big exception would be if clubs or courses would go back to letting younger kids caddy. I know that some places still do this (mainly in the Northeast), but I have found it to be less and less common. It is a great summer job for a kid and a great way to introduce him or her to the game, but it seems that a lot of players want a "higher end" caddy and not a kid that might screw some things up. You can pay kids a whole lot less and have them all carry singles and they don't mind the seasonal nature of the job. Most child labor laws exempt caddying, although there is still an age limit in most states (usually around 14).
However, if you want adults who are experienced "professional" caddies, you generally need to let them carry double or pay them through the nose.