I thought their main beef was with the owner being a bellend?
I posted about this on Reddit but it's not that black and white... he is a dickhead though however the hatred for him comes from many angles and for a multitude of reasons.
1. He is a supporter of the club first and foremost, his promises when he came in and why he got re-elected are because despite his weird attitude he gets stuff done and the club has benefited from it (multitude of trophies and achievements in other sports like Hockey, Futsal, Handball, Beach Football, Athletics and whatnot, don't forget Portuguese, Spanish and many other European clubs are more than just Footie Clubs.
2. He takes no shit from Media or whatever, when Tabloids etc talk shit he immediately hits back via social media or live interviews with said media, this can be good or bad but is generally perceived as him defending the club.
3. Corruption in Portuguese football is still rife, refs getting money or prostitutes in hotel rooms until recently, a main aide of the Benfica President found to have ties to drug dealers and found with Cocaine IN Benfica's official vehicle and I believe in their stadium... nothing happened - BdC (the Sporting president) is currently in process of getting rid of some corrupt individuals tied to Sporting like some Angolan investor guy who has like 18% stake in the club... that guy has connections to the Sporting Doctor... who once that happened resigned and put himself up for candidacy for the next Presidential Election.
4. The attack (very deplorable act) was said to be random etc but apparently was spurred by the fact when Sporting had a bad result to Maritimo which forfeited their CL place, the travelling fans booed (remember Madeira is like a couple hours by plane from mainland at least so it's at fair cost and travel) and once they got booed some players like Rui Patricio and some others made rude gestures to the support and told them to shhhh - NOT SAYING THIS JUSTIFIES ANYTHING but that there may have been a reason they were targeted (Bas Dost has said he was hit only because he was protecting others, he wasn't someone they were after)
etc etc... like I said, the guy IS mental and the attack WAS horrid and the guys need to go to prison BUT there is more to it than meets the eye, the reporting is all just about how crazy the President is but there is much more at play including other clubs smearing him to get rid of him as he's the only one who's publicly called them and the Federation and refs on blatant bullshit.
Bruno de Carvalho was suspended by the board today but he has refused to accept the decision because he doesn't recognise that board..
This is a little preview of what is going to happen when Trump loses the next election
This is what I mean about news are coming out but the info is already skewed... this is not an official board within the club, it's a board set up by a rival of his who will also compete for the Presidency, he is well within his rights to refuse it and take it to proper legal counsel.
Other players are signing new deals in other sports within the club btw and a new football signing was done the other day - like I said above, there is deffo more to this story and the news especially internationally are simply "the guy is crazy and it's all because of him" that's only like half the story if that.