Good point. I doubt he would have dropped an appeal if he thought he could win. Especially as Povol points out, he carries that black mark on his license for a year (I hope the 2016 title doesn't come down to Valencia for Marquez, because this could really set up a dangerous situation if VR went into the final round with a clean license). If Rossi thought he could win in court, it would have gone a long way in vindicating this notion that he has created of being unjustly victimized. So winning a court battle would look great. Thing is, the opposite (in a normal world) is true. That is, if he lost, which is likely, then it would be certainly a better PR damage control to "withdraw." I'm sure Rossi calculated his likelihood of losing this claim, and the upside in terms of optics is it looks 'gracious' to withdraw. Tell me his ardent supporters won't look at his withdraw with admiration, you see, Valentino is the bigger man.
Now speaking of the author, I suspect it was a good idea for the bloke not to have published his name, surely he'd be getting hate mail by now for the following part:
"Rossi was penalised for 'deliberately forcing another rider off line, resulting in contact causing the other rider to crash' on lap 7 of the Sepang race."
Its the first time I have seen a media person write it like this in one sentence. Usually they won't describe the crash as directly CAUSED by Rossi's actions. It had become debatable (as insane as that sounds) 'who' caused the crash.