At some point, you have to hold the person and figure out if they're a danger or not. Not everything is an unpaid ticket, and jail is probably unpleasant because everyone involved is unpleasant. Has it ever been otherwise?
>pay a bond which you will never get back (because you are too poor to pay bail.)
Why would you not get your bond back if you went to court as required? It would be forfeit if someone stops showing up to hearings, which is a requirement of their bond. It's to get them to return to court instead of just fleeing.
The bondsman guarantees your appearance, but often charges tons of interest or other fees that cost you that $5k, plus whatever collateral you can muster.
Apparently a handful of states bypass the bondsman approach by allowing defendants to post the 10% of the bond in cash to the court itself, and then refunding it minus small fees if the defendant makes their appearances.
Overall, I see where defendants come from but the courts want appearances, and failures to appear aren't rare: https://en.wikipedia.org/wiki/Failure_to_appear
(don't go to court if you can avoid it)
In the US, just as in Japan, as soon as you are arrested they begin punishing you. If there were a real assumption of innocence, jail would be pleasant and comfortable, and if you were WFH you wouldn't miss a day. There is a material presumption of guilt, even if there's some sort of ethereal theoretical presumption of innocence.
Instead, you're in a horrible cell, eating horrible food, dressed in a humiliating way, treated in a humiliating way, and exposed to dangerous people. Unless you can pay a bond which you will never get back (because you are too poor to pay bail.) You haven't been convicted of anything. The fine you're facing might be lower than your bond, and the time you're facing might be shorter than the time you'd have to wait in jail to go to court.