By the same argument, doesnt that mean there can be no reliable Turing machine either, as quantum effects and random perturbations means that eventually your machine will calculate some logical expression wrong (and that's before we talk about running out of tape).
Not really, the machine can be built to exclude all sorts of probabilistic results to any given redundancy level. Probabilistic algorithms still work on Turing machines.
What a standard Turing machine cannot do is entangle and superpose states. (It can only simulate it at high and variable cost.)
Remember that a Turing machine is an abstract thing. Building an ideal one is not possible. You can try though.
