The blank slate. The creative flexibility. The live/work aspect. And so much fun to re-imagine.
There's a reason why lots of creative people love the loft space. They're not confined to a finite layout--there are many possibilities to make the space your own without having a space defined for you.
1.
In a traditional house, the layout is what it is. Sure, you can convert the dining room into an office, but then you don't have a dining area. Or maybe you want a larger living space and one less bedroom, but the structural walls won't allow for this without major construction.
A loft gives that flexibility for creative vision. This is why you'll often see lofts become drastically different when they move from owner to owner. It might be 2 bedroom loft in one life, and then an open plan art studio or showroom in the next life.
2.
Then there's the general drama of a loft. The tall ceilings, concrete pillars, barrel ceilings, exposed brick, massive windows.
3.
The live/work status of most lofts. You might have an owner use their loft as a photography studio, or design space, or a dual live/work showroom, or just live in it. The flexibility of zoning as "live/work" adds value and a larger audience pool for buyers as well as renters.
4.
And of course the building itself, which often has an interesting history. Maybe it was converted from a toy factory, department store, or old bank building.