Very true, but I think that is another argument for students doing this right away - it's a great opportunity to teach students about the issues with numerical methodologies.
Students need a firm grounding in the analytical and empirical foundations of physics in order to comprehend the issues with numerical methodologies for investigating complicated physical systems properly, though. I've done plenty of work investigating unstable, nonlinear systems for which no closed-form analytical solution exists (they abound, of course, for any non-trivial problem). I'm not sure that having my undergraduate and basic graduate education "mixed up" with issues around numerical solutions would have made the work any easier to understand or deal with. It might have made it harder.
There is no reason they cannot be taught together, though, and perhaps it might be a better approach for some students. I believe that every undergraduate physics curriculum ought to have a senior level course in computational physics.