> may be taken negatively by the folks who put you in that situation

From the author's account they seem to have extremely supportive managers. Not only that, the business spent a lot of time and care helping the hire figure out if they are a good fit and with all that invested I am sure they'd prefer a shot at fixing the problem. I'd be a little upset if as a manager my report resigned cited any of the issues the author reported without at least allowing me a chance to work with them on it.

Also worth noting, the author is a senior dev.