Being respectful means first not dismissing people’s difficulties but making the utmost effort to figure out the problems they mention and their origins.A big problem we have (at least in the USA) is the opinion some people develop that respect has to do with not making anyone uncomfortable. That isn't respect, that is creating a dysfunctional mindset.
Being demanding is a large part of lean leadership and, to be honest, in most cases, all goes well and people respond... there’s always one in ten who throws up a fuss, makes tantrum and will accuse you of being disrespectful in your very requests.
Being respectful means making sure people can succeed to the fullest of their abilities.
as a leader, your first job is to teach people to change.
Fear driven culture that give mouth service to "respect" often create a climate in which managers find themselves fearful of being blamed for "disrespecting people" (which often means making someone uncomfortable). If they truly are being dis-respectful their boss needs to be dealing with that and helping them improve (which their boss should know because they are actually involved in management - but in many organization, probably most, the their boss would be clueless).
These management system concepts are all connected - weaknesses in critical areas create huge problems. If management doesn't know what is going on in the gemba they are suppose to manage, problems are very likely. Sadly this is often the case.
What you say is well put. We need to have high expectations and expect that people will rise to the challenge. And if people can't (with help and good systems) we need to find them a new position at which they can excel. Babying people isn't respectful to them or everyone else.
Helping people be as contribute is respectful. While ignoring poor performance is often easier for the manager than addressing the issue and helping the person improve doing the difficult task is what managers need to do if they respect people. And likely managers should be spending a lot more time doing this and eliminating other things taking up their time (unless they are in an amazing organization where coaching is a huge part of the managers job - in which case, wonderful).
I have written about this several times: Practical Ways to Respect People - A Good Management Culture Encourages the Debate of Ideas - Respect for People Doesn’t Mean Avoiding Any Hint of Criticism