I don't think Pentax is sticking to SLR because they've got some very special ideas. I think it's just pragmatic.
Pentax K has a flange distance of 45 mm (https://en.wikipedia.org/wiki/Flange_focal_distance). This puts Pentax in a tricky position. Making a mirrorless camera is nearly pointless if they want to keep their current lenses. And they're already a niche player with barely any adoption.
Their options would be releasing a fat mirrorless camera, providing an adapter and creating a new lens mount, or adopting an existing lens mount. All of these kind of suck, and would risk losing market share. The easiest option seems to just keep going.
Pentax K has a flange distance of 45 mm (https://en.wikipedia.org/wiki/Flange_focal_distance). This puts Pentax in a tricky position. Making a mirrorless camera is nearly pointless if they want to keep their current lenses. And they're already a niche player with barely any adoption.
Their options would be releasing a fat mirrorless camera, providing an adapter and creating a new lens mount, or adopting an existing lens mount. All of these kind of suck, and would risk losing market share. The easiest option seems to just keep going.