Is my ipad defective (safari prevents autolock)

Ipad 4th gen, 32gb, ios 7.0.3.

Close all open apps.

Open safari.

Leave safari open at the "blank" page.

Leave ipad unattended.

Notice that ipad wont sleep/lock even after 2minutes of non-use.

Great way to burn through battery and shorten screen life Apple!

I'm thinking this cant be a bug. It's too obvious/easy to repro.

No way the testers could've missed this!?

If this is expected behavior...why would ANYONE want such a feature???