That's fine if you don't have to move it very far or the surface is perfectly flat. But the weight of the bike is all wrong so it's pretty unstable even on a smooth train platform, and next to useless on a pavement (for example).
I've heard of people fitting skateboard wheels instead of the easy wheels to make this bit easier, but my heels only clear my easy wheels by mm anyway, so anything wider wouldn't work.
As I say, I was looking at mine folded the other day and wondering if there would be a way so that the front wheel is tucked in while folded as it is now, but if you pulled up the seat post and leant it back, it would hit the ground and you'd be able to roll it along.
It was just a thought as one of the great things about the full-size folders I used to have was that you'd could push them along really easily while folded (although it took less than a second to unfold). This was useful for me as I normally get on the back of the train to ensure there's space, which means I'm furthest away from the ticket barriers. In turn, with a Brompton, because of the weight, it's uncomfortable to carry for that length of time so I have to stop and unfold it to push it along, which means by the time I get to the barriers, I have to queue for ages.
It may be that it's only me that thinks it's a good idea though...