I wear a lot of t-shirts and non-collar shirts. When I do wear a shirt with a collar I tend to button down my collars. In terms of my ability to Chin Na, someone grabbing me my neck or shoulder area would probably encourage me to grab your hand and make sure that you can't remove it from my shoulder or my neck. In short, I don't have to go chasing that hand because you have just given it to me. Grabbing my jacket like a Gi would give you a better and safer option. My shirts also rip easily. The reason I know this is because I've ripped multiple shirts simply by taking them off.You don't wear shirts? A shirt collar works just as well as a lapel.
Companies don't make shirts as durable as they used to. I own t-shirts that are more than 30 years old. I use them to work around the yard. No rips. You can probably choke me and drag me down the street with the old shirts. But the new shirts? They won't last.
Exhibit 1:
Shirt rip during fight.
Exhibit 2:
Ripped shirt
Case closed - Kids ripping shirts?
They just don't make high quality durable shirts anymore. Every video that I've seen that tries to address the challenge of using a T-shirt to choke someone says "bunch up the t-shirt" then they take a lot of effort to do it in a demo, that I just don't see it happening while in a street fight. The time that you take to use two hands to bunch up a t-shirt is going to put the BJJ person in danger, because the hands are no longer trying to control anything.