There's being blunt, and there's being a
bastard (to borrow Linus' word).
True story:
I once worked in a place where a new trainee engineer was struggling with a piece of work. There were a few reasons for this that weren't their fault (not a lot of explanation of the requirements). Nonetheless, the work wasn't getting done as fast as the PM wanted.
Now, the PM in this case had moved across to software development from a post-graduate background in teaching, which I only point out to explain that this particular PM considered themselves something of a big deal.
(Having moved around as an independent contractor I'm fairly used to seeing small fish in smaller ponds that think they're the office genius, but this was next-level conceit.)
Anyway, they decide to let this engineer go one morning. Their prerogative I guess, but the PM shares with everyone later on that same day that they were able to steer this person in the right direction on the way out the door by kindly explaining to them that it hadn't worked out because "they didn't have the natural aptitude for engineering and would be better served pursuing a different career path".
Most of my gigs are in a fairly small city with a smaller community of engineers, so I'm used to encountering people a couple of years down the road. Sure enough, I never saw this person around again in any of the meetups or in any other gig, so I assume they left the industry based on this manager's feedback.
So yeah, bastards abound.