How well does it work to just throw in all the ingredients and boil?
Ah, One Pot Pasta....

As loads of bloggers, authors and cooks - possibly inspired by Martha Stewart and her team - have confirmed: dumping the pasta, sauce ingredients and a carefully meassured amount of liquid in one pot or pan will give you a "pasta and sauce" dish in ten to fifteen minutes.

And it works. Sort of. 

Your instinct matches my experience: when you omit the sautéing or slow roasting of ingredients you are missing the flavour compounds that this step creates, likewise if your recipe stews the sauce for a long time. So while all ingredients in one pot pasta will be cooked, due to cutting everything to the appropriate size, the flavour will be different from what your traditional method creates. 

If you expect one pot pasta to taste like your traditional recipe, you will probably be disappointed. If you are simply aiming for a creative, hassle-free quick dish, go for it.