Reasoning behind exceptions to Equality Act 2010?

More of a why than a what question...

I'm flat-hunting at the moment and I've just been told by a landlord that I can't view a property because of my age - I'm 30 and they want someone 35+. I was surprised to read that the 'Premises' part of the Equality Act 2010 does not apply to age discrimination and I can't really understand the reasoning behind it. I don't see why it would be unacceptable to discriminate based on age when hiring a person, but not when seeking a tenant - if you can demonstrate through references, financial records, face-to-face meeting etc. that you would be a suitable tenant (in a similar way as you would demonstrate that you would be a suitable employee) what would make it more acceptable to refuse to rent to someone purely because of their age?