It's manipulative only if there really is no redeeming quality to their approach, which, in any realistic scenario there probably is.
I interpret this as, not that you should lie, you should just NOT focus 100% on the negative aspect. At the very least you can thank them for taking the time & effort to implement this solution & test it or w/e (I assume they did "some" work & put in some amount of well meaning effort).
If I can't genuinely find anything to praise about something I want to criticism, it's a sign that it's pretty bad (or I have a bad working relationship with this person) and that is a bigger, separate problem
I interpret this as, not that you should lie, you should just NOT focus 100% on the negative aspect. At the very least you can thank them for taking the time & effort to implement this solution & test it or w/e (I assume they did "some" work & put in some amount of well meaning effort).
If I can't genuinely find anything to praise about something I want to criticism, it's a sign that it's pretty bad (or I have a bad working relationship with this person) and that is a bigger, separate problem