How would you propose punishing police who obtain evidence illegally? Police departments sometimes promise to do so, but if the agents' cases hold up, the agents aren't punished.
Having a court throw out evidence that a cop gathered illegally may seem a rather blunt "weapon", and it is, but it's the only thing that's been shown to actually work.
Problem is, it doesn't actually work. Nobody gets punished except the public at large.
For the record, I support the exclusionary rule, but Scalia makes a good point in his opinion that, in my mind, the dissent does not adequately refute. At the time that Mapp was decided, 42 USC 1983 wasn't an available option to those wronged by Fourth Amendment violations--it wasn't until decades later that 1983 actions were allowed against municipalities. So while the Court in Mapp (and the dissent echos) that there is no adequate remedy, that might have been true in 1961--but with the passage of 1983, is it still true? I don't know, but the dissent does not adequately address this.
I would propose specific laws that required police, DAs and others to hold those who commit errors in the collection of evidence as negligent, with ranges of penalties depending on how aggregious the error was and how high-up the knowledge and approval of the error went, from suspensions, with and without pay, dismissals, loss of pensions, permanent disability to ever again work in law enforcement and disbarment for those in the legal profession.
Root out the violators, keep the evidence.