The words "tough on crime" have a particular connotation, one which involves criminalizing minor offences then coming down with excessive punitive measures that are intended to deter crime. The end result is seen as being ineffective (punitive measures do not address the root causes of crime and will not alter the behaviour of some people) and is even seen as contributing to the problem (e.g. prisons may worsen, rather than reform, criminal behaviour; having a criminal record reduces opportunities that may steer people away from a life of crime).
If those words meant something different, such as people will be caught and expected to redress their crimes or prisons will attempt to reform behaviour and provide the tools to steer away from a life of crime after release, then being tough on crime would have fewer detractors.
And in many respects those detractors are right. The resources being invested into the current tough on crime measures would be better invested into addressing the causes of crime. It won't solve all of the problems since there are some genuinely nasty people out there, but there is a good chance that it would do a much better job.