Minitab's used a lot in production engineering, quality control, & Six Sigma (& when engineering companies use it in these areas, it may also have become the default statistical software in others).
Based on my experience, I reckon graduates worry too much about software (& not enough about other things, especially consulting skills); demonstrated competence in statistical programming is generally important, but lack of familiarity with any particular language/software needed for some job is easily dealt with after starting it. I would say, though, that a Minitab (or SPSS) user, rather than a SAS (or R, or Stata) user, has perhaps to take pains to show that they can do more than point & click to run canned analyses—e.g. writing macros for non-linear regression, or whatever's not in the menus at the moment.
Should you invest more time in learning SAS instead? Instead of investing more time in learning Minitab?—probably yes. Instead of investing more time in anything that gives you experience of working with real data on real problems &/or collaborating with domain experts in another field?—probably no.