Not to mention that letting the users mess with the settings of the default scans would exponentially increase the difficulty in troubleshooting problems with them. It would create a nightmare for the developers. If you want different settings, you have the ability to create them in a custom scan.
well following that same logic, wuldnt that create hell for devs with anyone using a custom scan? so shuld they take away even that?
Not really since the developers could tell the person to run a default scan and see if that works okay. Then if it does, some potential causes would be eliminated and they can get down to asking what the settings of the custom scan were that differ from the defaults. With the old version, the default settings did not show so the user would not know what they did that was different.
If the problem was with the default scan then they would know what to check without even having to ask. If the user was able to change those defaults, then that would create more problems.
The real point is that they didn't take anything away. You never could change the settings for the default scans and didn't even have a way to know what they were.