@BustPipes I'm a "Hell, Yes" 
But as with the bifold "debate" - essentially just a type of door, doesnt it depend on the type of island you have and the size of the room its in?
Before my long awaited extension, my kitchen was 4m × 3m and due to really awkward layout and massive chimney breast, it felt tiny. U shaped kitchen with 2 utterly pointless crap corner cupboards. No view, only room for the smallest table in the world, freezing. Island? Ha ha.
Kitchen is now 7m x 7m or thereabouts. Have room for island, table, seating area. I wanted a linear kitchen to avoid useless corners, with an island in front of line of units. Its 90cm by about 2.4m i think so pretty big. Masses of (useful) cupboard / drawer space, used everyday for breakfast (dinners at table), prep space, if i work from home, kids doing homework, -having a coffee looking through bifolds-
then as perching spot when we have friends over.
As i said at the beginning, its about how you live your life. For us (and everyone is different) it works - the island enhances how we function as a family. If it didnt, then yep, i agree, there's no point!