All scientific software should be totally open and transparent -- indeed a lot of it already is. For years, for example, people were erroneously making the mistake of trusting Excel's statistical functions without being aware they were deeply flawed.
Software that is in use for scientific purposes must be open to review and assumptions about their efficacy or correctness should not just be taken for granted. They need to be checked and their outputs verified for correctness.
Even when flaws in commercial proprietary code are found it can take years (or never) before they are corrected. Chances are that if the same flaws show up in OS software they be fixed sooner. Failing that, you can fix 'em yourself -- or at least be in a position to potentially detect them and alert other users.
Software that is in use for scientific purposes must be open to review and assumptions about their efficacy or correctness should not just be taken for granted. They need to be checked and their outputs verified for correctness.
Even when flaws in commercial proprietary code are found it can take years (or never) before they are corrected. Chances are that if the same flaws show up in OS software they be fixed sooner. Failing that, you can fix 'em yourself -- or at least be in a position to potentially detect them and alert other users.