Having Nathan walk everywhere by default is tedious. We can all agree on that, I think.
But I now believe that was an intentional design choice -- he's not a hyper experienced hunter yet, and when he starts the game, he's down a team member and a mentor, and his powers and equipment are both lacking. The game WANTS YOU TO FEEL THAT, so Nathan inches along slowly and deliberately. He's not rushing headlong against impossible odds. He's moving at a considered pace that gives you (and by extension HIM) time to observe new threats and some of their behaviors before committing to an engagement when traversing an unknown area.
This kind of got reinforced in my last playthrough where I, having fully forgotten the map in its entirety, entered the Chapel and just SPRINTED (like I always do in video games) and damn near constantly either collided with or aggro'd a monster that I would have seen and had time to register had I approached at a walking pace like the game wanted.
Blitzing your way through the Castle is for when you've built up your power considerably and have memorized the layouts of each area (or at least have learned to anticipate some of each areas design choices).
And knowing that? I really feel like COTM is the only portable entry that really understood the design of the NES Trilogy enough to try to duplicate it. Your mileage may vary on how well it actually succeeded, but this is still pretty neat to have realized.