Python's whitespace-as-logic means that, for any given project, every editor used by every developer needs to have the same the same definition of what a "tab" is, because mixing tabs and spaces can introduce logic errors.

You can reasonably argue that a project team should already have and enforce a coding style guide, so specifying a "tab" isn't a big deal. But what if you're part of two separate projects which different coding standards? Do you use Editor A for Project A, and Editor B for Project B? Or do you maintain separate configuration profiles, one for each project? Granted, this also isn't a big deal: Just "git checkout ProjectA" in the directory where you keep your preferences before you start coding. But it is an extra step in your workflow.

You can use the "-t" or "-tt" flags to spit warnings or errors if someone mixes tabs and spaces, so any conscientious group can easily catch whitespace incompatibility problems. But Python's whitespace usage has organizational consequences, and it can affect a developer's choice of tools and/or workflow. For some people, this is not a superficial impediment.