It's not about Pirelli being unable to make tyres last, they could make a tyre last the whole race. They were required to make tyres that would degrade fast this season. It's a tricky balance, they were aiming for 3 stops and nearly achieved this so yes the tryes were a little too soft.
Because Merc get heat into their tyres immediately they were able to take pole and that's exactly why they were useless in the race. The good news is that Red Bull aren't having the best time with the tyres so at least they didn't run away with the race.
All Pirelli have to do is use this experience to get the compound just right but it's a lottery as a few degrees C either on race will make them look good or bad.
The Pirellis on my car are great BTW, certainly the best RFTs I've suffered to date....

