Why would you compare Rex's introductory cutscene in XC2 to a cutscene in the original game that happens an hour in?

Rex's introductory cutscene is a direct comparison to Shulk's introduction. Both of them are in the wilds salvaging materials for their jobs. Shulk is collecting Mechon parts to develop weapons with while Rex is salvaging parts to sell directly, then they both get attacked by some crab monster. In Shulk's case, Reyn comes to his aid and combat starts while Rex has to fight alone since Azurda can't do that much to help him.

I feel The Attack on Colony Nine is most analogous to the sunken ship you explore at the beginning of XC2. Both sequences introduce the villain team, give the hero their sword, and set the hero out on their journey. I do agree that The Attack on Colony Nine had a greater emotional impact since it occurs suddenly after a couple of hours of gameplay, long enough for the players to get properly attached to all the playable characters.