I feel no need to label individuals as 'lazy' when their behavioral
choices differ from my expectations and fail to feed my need for affirmation.

It's not your expectations that are called into question. It's the expectations of their parents, and that falls back on the school, (our employers) who then feel the need to channel those same expectations onto the FT.

The school wants to know why the student's parents are complaining that his or her English level hasn't improved under your instruction, so the adjective often used by all is, 'lazy'.

Every FT who has worked in China understands the pressure that is applied to students. Parents across China spend trillions of RMB every year on education because they see it as some kind of dutiful 'investment' in their child's future. After all, what responsible parent doesn't want 'the best' for their son or daughter?

Those parents want to see a 'return on their investment' by way of progress, and are quick to blame anyone other than their child when they don't see any.

So what other adjective are you going to use?

If you try 'unmotivated' then you are likely to get the reply 'Well motivate them', or if you say 'uninterested', you will get 'Well make them interested' so it's far easier to say 'lazy' which then absolves the FT of any blame.