yeah, I was wrong. I don't know how much more help having the DRS open for the full straight would have helped though - it was already the longest of the season by a fair margin. Certainly would have helped the Red Bulls if they were allowed to open it before the final corner as they were doing in Qualifying
The Ferrari donk is bloody quick as was the Mercedes and the Red Bull was so fast through the final corner onto the straight that for different reasons those cars up front behind didn't get a chance by the end of the straight. Add in the aero wake disrupting downforce and preventing anyone from really following close through that final corner and in hindsight it's not difficult to see why it didn't work.
I think the times that DRS has helped drivers has been on straights when speed through the previous corner wasn't governed by downforce (Sepang: final corner was a hairpin, Shanghai: Hairpin into kink onto straight, Istanbul: slow corner into kink onto straight) because 1) the following car suffers a loss of aero grip from the wake of the car in front and thus can't follow as close as needed and 2) The Red Bulls despite having the slowest donk are getting a big jump on the car behind. KERS doesn't help the situation but then again all of the main teams have it available (unless it has failed) so it shouldn't make any noticeable difference.