The reason USC fans are upset is as follows:
HOOPS
One player (OJ Mayo) was investigated by USC with assistance from, I believe, both the Pac-10 and the NCAA prior to enrolling at USC to ensure he was eligible without any recruiting issues. After being cleared, he played for a year and then left for the NBA. USC was later penalized for recruiting violations (in spite of the earlier investigation and clearance) and for the player receiving extra benefits. The basketball team self-sanctioned and those sanctions were accepted by the NCAA.
WOMEN'S TENNIS
One player from Europe (don't know her name) took an athletic department credit card and made multiple calls home over a several-month period. The team self-sanctioned for this extra benefits violation; those penalties were accepted by the NCAA.
FOOTBALL
One football player (Reggie Bush) and his parents took extra benefits for a year (or slightly over--the actual date the extra-benefits started was disputed) from 2 would-be marketers who were not affiliated with USC and who were located in San Diego, over 100 miles away from campus. There was no evidence that USC was aware of this, with the possible exception of one assistant coach (Todd McNair). That coach received a one-year "show cause" penalty because the NCAA decided he "should have known" what had occurred by learning it after the fact. Their basis for that decision was a single photo taken in a public place and a late-night phone call. When the coach was asked about the phone call, the NCAA gave him the wrong date and never corrected this mistake. Their primary "witness" was one of the 2 men in San Diego (an ex-con) who was in the midst of suing Reggie.
Coach McNair is suing the NCAA for the lost income and loss of reputation (he was unemployed for 2-3 years). The judge in the court case gave an initial ruling that emails obtained from the NCAA show malice towards McNair and are reason for the case to proceed and the emails to be publicly released. The NCAA is appealing that ruling. The LA Times (and I think one of the other LA papers) have also filed FOIA requests to see the emails.
Bush also did an internship his junior year (with Mike Ornstein) which the NCAA ruled an extra benefit because it wasn't an internship widely available to general students. They also declared Ornstein was a booster even though he had no previous relationship with USC.
Pete's brief hiring of a long-time (and recently unemployed) friend to consult on ST was deemed an extra coach and a secondary violation. The NCAA then switched it to a major violation and rolled it into the LOIC charge.
Recruiting dinners at Papadakis Taverna were deemed violations because the owner is a former USC football player and had addressed the recruits. This violation had already been addressed previously by the NCAA when they decided to throw it in to boost their charge of LOIC.
USC did not self-sanction the football team because they felt they could not have known what was happening with Reggie. I think they also disputed the ruling that Ornstein was a booster, though I can't say for certain. As mentioned, the extra coach and the Papadakis Taverna issues were supposed to be minor and previously addressed. According to what I've read, which may or may not be true, the NCAA has previously held that penalties cannot not be assessed in cases where there is no way for a school to know violations were occurring.
USC was lauded for their compliance education of their athletes. The report also stated that the school fully cooperated with the NCAA investigation.
USC waited over four years for the sanctions to be announced. Rumor has it that the NCAA was trying to wait for the results of Reggie Bush's court cases with the 2 San Diego guys so they could grab the sworn testimony (sound familiar?). The cases were settled out of court, however.
When the sanctions were finally handed down, Paul Dee made the now infamous statement about high-profile athletes needing high-profile compliance/monitoring. That standard is not spelled out in any NCAA rule and was literally made up by Dee and the rest of the Committee on Infractions. It wasn't applied prior to the USC case and has never been used since. Dee also stated that the open atmosphere at USC was "troubling" (open practices, etc.) even though none of that had contributed to any of the violations. The COI included a member from Notre Dame, one of USC's primary rivals and a team that hadn't beaten USC in several years, as well as someone from Nebraska, a team USC had embarrassed twice in home-and-home games in recent years. The Notre Dame representative only recused herself from the discussion about a possible TV ban. Chairman Paul Dee was the AD at Miami during the time when several infractions had occurred (or were occurring) at that school.
After rolling everything they could find into LOIC, and already accepting the self-sanctions for the basketball and women's tennis teams, the NCAA vacated UCS's BCS Championship (Orange Bowl) and all games from the 2005-2006 season. They declared a two-year bowl ban (which ended up including USC being banned by the PAC-12 from participating in the 2010 P12 Championship even though their rules do NOT preclude it), loss of 10 scholarships a year for 3 years (30 total) AND a cap on the total number of scholarships per year from 85 to 75, "free agency" for 2 years that allowed juniors and seniors to leave without penalty, and probation through 2014. USC returned the crystal ball trophy and their copy of Reggie's Heisman trophy. Reggie ultimately also returned his Heisman, and he has been disassociated from USC by NCAA decree.
All of that for ONE guy.
Tell me how Miami's sanctions are harsh by comparison when their infractions involved a major booster paying recruits and players with full knowledge of multiple people for nearly a decade?