No I am not in agreement (nor are some others in this thread)
Do they need tweaking for collision avoidance (especially for rear shunts), yes.
As Sniper420 said earlier in the thread, once you get used to how they do things, it's generally a very good experience. Like him, I have had in F1 2015 some the best AI battles I have ever had in this series of games.
Back markers ignoring blue flags can be a bit of a pain, but they are just as bad to everyone, not just you. I had a scintillating battle with Hamilton @ Mexico yesterday, I've never run that track before, but it's in my top track list now, I love it.
I was 3.5 seconds ahead of Hamilton and got screwed by a Force India I lapped near the DRS sensing line. He zipped past me on the home straight under DRS, then successfully broke my composure for the next 3 corners. This allowed Hamilton to catch up, and start a 20 minute nip and tuck race between the both of us. Side by side into corners, he jumps me at the pit stop, I get him back, he then DRS's me, I then DRS him and so on. Tip top fun was had by me. Eventually Hamilton was adversely effected by a back marker, and I went on to beat him.
You only have to listen to Raikkonen's pit radio in real life to see that back markers are not perfect there either
Sure you can expect a bit of mayhem at Monaco, and a few re-starts, but generally I'm liking this feisty AI.
Do I get angry sometimes? Yup, but I've got blood pressure pills for that!