He didn't even get to see the barriers or wherever there was space to stop without crashing, because people were in the way.
You can even see that 2 meters to (Remco's) right, the barriers stop and there is more space, so he had some more meters of braking over there (if people weren't in the way and if he saw that space).
Without people, he could have crashed in the barriers but at least those barriers were a further 5 meters from where he crashed, and 5 meters is enough to stop from 20k/hr to 0 k/hr.
Having people is very confusing as you don't know if they will get out of the way or not, and what's behind. It has already been said that this was the first day the organizers allowed more people in the mixed zone. Until now, only soigneurs could be there, but on Arinsal, they allowed reporters etc. to stand there. There was already max. 70 meters from finish to barriers (and the barriers were there to protect a fixed camera, the irony), so why did the organisation think it was a good idea to reduce 70 meters to 50 meters, and have some stewards there (see here, in green), to make riders go in a 180 degree curve to the right (that obviously no rider seemed to understand how to physically do this)? The way the stewards were trying to divert riders, proves that they were simply naive thinking riders would take that turn.
For me, the organisers could have prevented all of this. Remco could have not made personal mistakes and he is partly responsible, but why does the organisation f'$% this up?
Because they are simply incompetent? There was a 42k/hr finish, over a small crest, into a slight left hand curve, going downhill, with 50 mtrs of roll out distance. That's less than 5 seconds, with a reaction time of 15 meters and a braking distance as much as 15-20 meter. Not exactly a star move from the organisers to design it this way (they could have moved the finish to the very crest) and organise it with all kinds of people in that zone that have no business there. What could possibly go wrong?