Ok, so you're just explaining this badly. The problem is not that "manual tasks" exist, but that they can be created with (false) dependencies on other tasks that have flexible scheduling. The way you originally explained Manual Tasks naturally leads to a perfectly valid use case, but apparently MS Project also allows for an invalid usage of that feature.
I'm really not. You're just doing that very-very-HN thing where you assume your surface understanding is sufficient.
Manual tasks in MSP are a very bad idea. There is no valid use case for them in critical path scheduling. They exist because some muzzy-headed marketer at Microsoft decided to insert them into the backlog, near as I can tell, despite the cries of actual professionals who use the tool.
There are ample ways to model constrained tasks in a critical path that do not involve a feature that is, as I said, tantamount to turning off "math" because you don't like what it shows you.
I'm finding it really odd how you are still insisting so vehemently that it's a horrible misfeature, and yet you haven't described what you consider the proper way to represent immovable parts of the schedule, and have barely even acknowledged the need for such a thing. Please, tone down the ranting and try to explain this stuff in a useful way.
> There are ample ways to model constrained tasks in a critical path that do not involve a feature that is, [...]
Can you finish that paragraph in an informative manner?
This is Microsoft that we're talking about, so I don't doubt that they could put in a feature that is as horribly misguided as you claim; I've encountered a few myself. But you've really just been repeating your original assertion without justifying it, and that's unhelpful. Getting haughty about it is even less helpful.
