If you really cleaned up in the sense you're proposing, town would be a lot, lot quieter, a lot less business and the knock on effect would take its toll.
Ask a cabbie what it's like when the students go home.
The city is far too dependent on the leisure industry, anything that has an impact on the fragile relationship between students, clubs, bars and pubs will have a massive consequence.
Would genuinely like to hear from police and council as to intent and actual achievement during these raids, including arrests, contraband or chemicals impounded and costs per prosecution from raid to court