Dead ends are there for a reason to create a sense of a larger world. They are usually blocked by some logical obstacle, and rarely actually lead to a short alternate area, but not an alternate path. Half-Life is linear by design, surely you must agree that a linear path that tries to create a bigger world is better than one without. Those paths perhaps broke the illusion for you, but at least there was some illusion and without the paths there would be none.
I agree with the first paragraph, the first game was better since it didn't constantly trap you in rooms, where you had to wait for dialogue to play out, which were just glorified cut-scenes. For example, in the first game if a friendly character tried to convey some dialogue you could ignore/kill/avoid him, but in the second game you can only wait.
There were plenty of situations in the first game where you had to wait for a character to finish his dialog and open a door or something so you can progress.
I agree with the first paragraph, the first game was better since it didn't constantly trap you in rooms, where you had to wait for dialogue to play out, which were just glorified cut-scenes. For example, in the first game if a friendly character tried to convey some dialogue you could ignore/kill/avoid him, but in the second game you can only wait.