It may interest readers to know that under current sentencing guidelines, the offence of Possession of a Bladed Instrument shows a "starting point" of custody for a first time offender.
New guidelines are due to come into force on 4th August and, among many other changes, the starting point for that offence has now been reduced to a Community Penalty.
So far from an automatic jail sentence for the offence, scorpius it will be less likely that such offenders will go to prison.
The issue of the gentleman you describe being bailed for such an alleged offence is quite separate. Apart from the most serious offences (and this is not among them) judges and magistrates do not consider the seriousness of the offence when deciding whether to grant bail before conviction. They only have to consider whether the accused is likely to commit further offences, fail to appear for the next hearing, or interfere with witnesses.