Didn't they get the memo that this is not so good security measure? Why are they still insisting on it?
These days when you buy a new laptop from one of the big manufacturers it is fairly common for it to have the harddrive encrypted with bitlocker.
If you don't create a Microsoft account and later the laptop stops working and you want to read the harddrive or ssd in another machine, uh oh, you don't have the bitlocker key, you have lost any files you did not have backed up.
Some models of laptop intended for corporations have an option to erase the TPM if the laptop is physically opened. You opened that laptop to see if you could add more RAM? You need the bitlocker key to get your files back (or you need to restore from backup if you have one).
The FBI wants to be able to access and forensically image devices that they have seized. If Microsoft keeps a copy of bitlocker keys in Microsoft accounts then they can also give them to the FBI and other spy agencies.