Schiaparelli was never a science mission. It was a technology demonstrator to see whether the landing system worked. Even if it had landed intact, it had a tiny set of science instruments and would only have lasted a few hours.
Well, we now know that there are a few bugs --- but we also know that most of the landing system works, including hibernation, terminal guidance, reentry, heatshield deployment, the parachute... all of which is hugely valuable data. Knowing that the last few stages didn't work is even more valuable, particularly as it's returned telemetry on what happened.
Focusing only on the fact that the last couple of steps failed and it crashed is doing the mission a huge disservice. Schiaparelli did precisely the job it was designed for.