"Too tough" means "I didn't get the grade I wanted." Grade inflation is a real problem.

Agreed. When I was teaching before I started out as a developer, it was unheard of to fail anyone in an entry level Physics class (granted this was an Ivy League school); over many semesters I recall thinking that we had passed several students that had no business advancing "because medschool needs high GPAs" or because we didn't want to ruin some kid's future in engineering (when they may not have been successful anyways). But yeah many (most?) of the kids care about a high grade before learning anything, and expect nothing less than an A, even if they don't deserve it.