Social media is a huge time waster. The rise of social media has helped a lot of things like marketing and recruiting and newsgathering. On the flip side, if it wasn't for social media, cyber bullying probably wouldn't exist. Then there's the rise of fake news... and the fact that adults all seem to have ADHD now because no one can focus on any one thing for more than two minutes at a time thanks to constant stream updates.
So all that said, I completely agree with why Nikki Sixx deleted his social media accounts. Basically he said he was spending too much time on his phone and not enough time on creative endeavors. It's interesting, because social media is amazing for music marketing and SIXX certainly had a massive footprint (over 700K Twitter followers alone), so I believe this was a calculated risk. He knows his core fans will be there for him regardless of a Twitter account or not. New musicians don't have this luxury. Balance in all things I suppose.