Please don’t forget about the children. Many children have a very stubborn streak when it comes to food. Some will eat pasta every day without fail and nothing else because that is all they choose to eat. Should we let the kids starve and not eat? All these new concepts allow parents the opportunity of satisfying the family while still teaching them the proper halachas and training them about the JOY of yiddishkeit.
Not every adult is running out to buy these items for themselves because THEY can’t do without them. But easing children into Pesach minhagim will help them enjoy Pesach and not resent it. I am quite sure that there are many adults who will buy these things for their kids but not eat it themselves. I have tried Pesach noodles in the past and found them lacking in taste and any resemblance to chometz ones. So buying these products will not necessarily satisfy the adult pallet yet parents have the option of these items for their children until they can understand the concept of doing without it for a week. My Rav when I was a child, Rabbi Kirzner z”tl used to give his pre-pesach drasha and say “Kinderlach, si doch nor ein voch!” It is only ONE week.
On the other hand, I agree with Oomis, there is nothing wrong with using products that resemble chometz if it isn’t chometz. The halacha is not to eat chometz or even look at it. There is no halacha that says don’t eat anything that looks like chometz. So why judge those who do or companies who have figured out how to do it? Why do we have to hold on to the shtetel? When I was a kid my Mother never used garlic on Pesach. I grew up thinking that garlic was chometzik!!! So should we not avail ourselves of fresh garlic and garlic powder to cook with today? For that matter there was no garlic powder, onion powder, etc. 4 generations ago or ketchup, mustard, vinegar, mayonnaise and many other products we wouldn’t dream of going without. Our grandparents could raise the same question you did regarding our regular staples.