I think the problem with Olive Garden is not so much their basic recipes, but their execution. Maybe they are underpaying cooks and servers, or maybe nobody there cares. I am often dragged to Olive Gardens for work lunches, and it is really uneven.
For a place that specializes in pasta, their pasta is often gloppy, overcooked, old, cold in the middle, or just "wrong". I think that varies from location to location.
The infamous all-you-can-eat salad
Pasta Fagioli soup
"Griller" steak thing
Tiramisu (thiugh I did get it still frozen once).