In every walk of life, at work, in hospitals, in law, in prisons, everywhere I can think of repeated mistakes are punished with increasing severity. A doctor who makes a mistake and kills someone, unfortunately that will happen, but they guy who accidentally kills one patient is treated completely different to the guy who made his 5th mistake killing a patient, you lose your job, maybe even face charges of neglect.
If you get done for assault, the first sentence will be much lighter than you would get for a second, then third, then fourth attack. Kids getting into trouble at school, first thing, maybe a detention, second thing, sent to the headmaster, third, maybe a suspension, 4th, maybe you get expelled. You don't necessarily have to do something worse, but repeated offences are treated worse in effectively every part of life.
Why, because as humans in general we're supposed to learn from mistakes. Football is the same, in every type of rulebook repeated offences are treated worse. First red card for violent conduct is a 3 match ban, second red card for violent conduct is a 4 match ban(which is more likely to be increased further), etc, etc.
What Moses, and lots of other liverpool fans are doing is treating biting, alone, with no connection to his previous offences which is delusional. In every single situation in life a third offence is treated worse than a first offence, but Liverpool fans are making the argument that a bite is less bad than other things. It doesn't matter, because we're talking about a third bite vs a first bad tackle/whatever else.
Fifa have stated the panel reviewing it can take into account his previous actions, hopefully they won't back away from that and be soft on him because he doesn't deserve more chances.
A ban is fundamentally, like any punishment, supposed to teach a player, and others watching, that the behaviour is unacceptable. The fact is a 7 match ban, then a 10 match ban did NOT teach him this lesson.
What other offences you can be banned for and how bad these other offences are completely and utterly irrelevant, Liverpool fans and crap journalists are bringing them up in an attempt to make biting look less bad, while ignoring things like it being his third(with seemingly potentially many more attempted) bite, and ignoring that it proves his conduct has not improved despite constant promises from Suarez that he's better than he was. This bad conduct not only includes biting, but stamping on players frequently, intentionally injuring players and occasionally breaking players legs.
The behaviour that leads to him biting is the same behaviour that leads to him breaking other players legs, Suarez should either be punished until he stops that behaviour and we already know that 10 game ban won't cut it for a fact, or he should be prevented from being on a pitch at all.
