I completely agree with what you are saying, I have been dealing with Autodesk products over 26 years and this is now the 5th time that I've discovered an issue that seems to have been missed in testing, with the responses back from the forum and even Autodesk being it's your problem and you need to sort it out.
I have been in the fortunate position of resolving 2 of these issues myself and then had Autodesk contact me for help, when others reported the same issues, at which point my response has been its you product you sort it out!
I have relented in the end and given them the resolution especially when our reseller called basically begging for the answer as they had 2 clients with the issue and not being able to fix it was making them look bad.
As for your problem are you able to run an elevated command/powershell prompt and type in whoami /priv
once it returns the list of privileges do you see that you have access to
SeBackupPrivilege (state Disabled)
SeRestorePrivilege (state Disabled)
I was unable to install the product until these showed on the local system.
Hope this helps.