I’m totally crazy about the hind but that photo has been altered, I suspect the dismounts weren’t actually there in that photo.
Notice that for the photo to be real the sun has to be in two different locations.
also usually when you try to make equipment that can pinch-hit between two different roles you get you end up with crap.
The Hind is a weird exception to this.
I think the Hind is a case of noticing that a design had leftover capability and the designers just decided to use it, i.e, the helicopter had to be a certain size to accomplish its design goals with the technology they had on hand, so the designers realized that might as well add a troop compartment as it would essentially be a ‘free’ enhancement.
To be scrupulously fair, the 8 passenger cabin on the Hind is on the cramped side for a transport helicopter - a Western 8 passenger cabin would be much larger and more spacious.