Im going to bring in some previous clan experience (12 years cough cough no brag) into this and talk about the reason why no collision is a very bad idea/what it takes away from the game.
No collision was created back in the good old days solely to prevent any stuck issues inside of CSS. People who were by themselves in surf maps suffered all the time from getting clipped into ramps and had to restart their progress because they were forced to reconnect. So people brought this feature on to solve that issue.
Some clans started to implement this feature into Jailbreak servers to solve the same issue, but created a bigger issue on top of that. CT's found it more difficult to shoot the rebelling T because he would stack with the person next to him, thus causing the CT to free-kill. Other things this took away is chicken fight, which is a game where you try to jump on top of a T's head first to either win or gain LR.
Other issues this has caused is sometimes T's (mainly in Razor because fuck that map with no collision) would stack together and the person with the pistol cell would grab the gun, stand in the stack, and start to shoot at the CT's. Some dumb CT newbie would shoot into the stack, mass freekilling, then getting banned. Yes, they shouldnt be shooting into stacks, but then you're gunna have to add that rule to the motd and it needs to be clarified properly and blah blah not needed stuff etc.
With collision, you dont have to worry about that stuff. Sure you might have to type !stuck, but I believe they changed the plugin so that only one person has to type it and the person gets unstuck. My personal opinion, !stuck is a lot simpler than taking away games, worrying about CT ban reports, MFK's and missing out on one of the best mini-games in Jailbreak.
Just my amatuer opinion.