Giving bail to repeat offenders who are likely to commit more crimes while awaiting trial helps to boost crime statistics, which leads to more cops being hired. If all of the criminals were in custody, we would need fewer cops and fewer lawyers, and cops and lawyers certainly don't want THAT.
It would also cost society a shitload of money. Let me explain.
Denying accused bail means that they can't work. So their bosses would have to hire and retrain replacements. Costs $$$.
Denying accused bail means that we have to increase the # of judges because currently most people YOU would detain without bail couldn't get a trial within the likely duration of their post conviction jail sentence. So to make the no bail system make sense, you'd have to triple or quadruple the # of courtrooms and judges and courtroom staff to provide super fast trials.
Plus, that doesn't even begin to deal with the legal ramifications of no "presumption of innocence".
Plus, what about the guys who are actually innocent. Let me give you an example. Your bitter ex wants you to give her $10k for "spousal support" so she can fly to Jamaica for the winter with her new fuckboy. You tell her to gfhs. Next thing you know, she's called the cops and you're sitting in pre trial detention for 6 months because she said you beat her up.
You get to trial and the judge figures out the sullen bitch is lying and acquits you. But you now have no job, no career and no one will hire you because you have to explain why you were out of the work force for 6 months and admit you were in jail.
Yup, that's the fucked up world you will create for everyone. No bail is a great idea as long as the people who get fucked over exist in your imagination and they're all hard-ass criminals who "deserve a harsh lesson". But that same system also gonna apply to you, your buddies and your nephew Alan who's trying to land his first job as an accountant and will lose his career.