15,000 is a bit off. According to Wiki, they averaged 30,000 in the 83/84 season. Didn't have data for any season before that. But come on, that's almost 40 years ago anyway.
According to the Home Office, Newcastle had fewer football-related arrests than Southampton last season, despite having 25,000 more fans at each game. (See here:
https://talksport.com/football/447819/premier-league-football-arrests-201718-season-club/ )
Regarding Ashley, I don't think it's really fair for us to judge the situation. We don't know the real story, the ins-and-outs etc. We only see the headlines. It's like when fans of other clubs criticised us for sacking Puel. We knew the truth, but it was understandable why it looked strange to others.
The fans on here don't concern me; there are knobs in every fanbase.