If housing benefit went directly to the landlord, then the excuse of arrears would lose it's weight in "No DSS".
The problem (as many people on this thread have stated) is that if the council pays the landlord direct, and the council then decides there's a problem and either stops payment or reclaims it, the landlord loses out.
If the council pays the tenant who then pays the landlord, the council have to try to get falsely claimed money back off the tenant, and the landlord's money received from the tenant is safe.
(Also, hb is often less than the rental amount, so tenants have to make up the shortfall).
When I was a tenant on hb paid direct to me, I paid my rent on time even through delays in getting hb (taking the financial hit myself, putting everything on credit cards, barely scraping by without enough food til the payment eventually came) because having a roof over my head was important and I didn't want to risk being evicted (I also had a guarantor, and would have sooner starved then have them chased for money). Hearing all these stories of hb tenants taking the piss is really saddening.
I hated the 'no dss' thing. I had no choice but to get hb to survive, and I would never have dreamed of acting the way some hb tenants obviously do.