Back in the day this was common and many students didn't appear too stressed mainly because they were no uni fees / £1000 per year. Also, it wasn't that expensive to find somewhere to rent.
I don't know how / why students who don't have a TC or BVC lined up would want to take the risk, inparticular those with 2:2 from the newer universities. £50-60k debt from uni, incurring high interest and taking on another £15k of debt plus living costs only pays off if you land a decent job which often isn't the case. Are students told what the wage is likely to be for those not working in the city / commerial law firms?