I do not believe the game encourages crashing. I may be surrounded by highly skilled drivers, but they do make errors, I certainly do! While they may be fast around a lap, only a handful know how to race and give racing room properly. The difference being is that none of them believe crashing gets you places.
Anyone who crashes regularly and deliberately do not end up at the sharp end of the field. It is one thing I learned straight away, and to get my DR up, I concentrated on finishing races as cleanly as possible. It wasn't until I was well into my hundreds of races that I picked up my first win, and that was largely due to the matchmaker dropping the competition. (Appears as though the matchmaker tries to run a mix from A+ DR downwards. When you hit A+, you may end up as the fastest driver in the field as you may only be matched by yourself or one other A+ driver. Before that, even in A rank, you will get matched with 2-3 A ranks, as well as 2-3 A+ ranks, so a lot more competition and most likely faster than you)
And the multiple account phenomenon is an interesting one. I consider myself a clean driver, I try my best to get home without a scratch or a dirty tire every time I head out to track. With A+ drivers as fast as myself, I know when they will brake and what line they will take. Therefore I know how to run side by side with them, or bumper to bumper, inches, without touching them.
But, put a B driver in front of me across the top of Mt Panorama, and I often can't help but tap them. Not trying to pass them, not doing any crazy moves, but just bump them all the time. The difference is they are braking in unpredictable places as that is their pace. So I imagine a fast driver coming through the field would find the same problem. Unintentional, but seems rude as they are 'the fast guy trying to barge on through'. Have learned now and sit around 1 second back until approaching a straight then close the gap for the draft and a clean pass. Costs me time? Sure, but if you can't pass cleanly, you shouldn't pass.
So I imagine if you put a couple of B or D rank drivers together, and they try to run close, they will bump each other, as one driver is faster on one corner and the other is faster in another, but overall, they lap at a very similar pace. Would seem like bedlam as they try to mimic close racing as seen on TV/Streaming/Life etc. May give the impression that crashing is the way to get ahead, where the drivers are stepping over their limit without realising.