The government doesn't want their employees to share government information through other methods of communication such as social media. That policy has been in effect for years. Since the NWS is under the Department of Commerce, it must comply with all government rules. It would face huge liability issues if employees tweeted official weather information on their own accounts as someone could accidentally or intentionally spread faulty information and create unnecessary panic in the public, which could lead to lawsuits and other legal issues.
It's better that the NWS sets up a few regulated accounts to pass along information so that the public knows these are the only trusted and official sources among all social media accounts. I really don't feel this issue is such a big deal, Ana. There's already many other ways that the NWS sends out information to the public. Personally, I prefer the weather radio for the fastest way to get information if you don't have time to look up the NWS websites. It doesn't need an internet connection, and it alerts you when a warning is issued for your area.