Of course there are no grandmothers making these soups, they are made in professional kitchens by professional cooks, off of a recipe designed at corporate headquarters and thoroughly tested to make sure they appeal to the lowest common denominator of diners (That'd be rpeate for those keeping score at home.) People don't go to the Olive Garden for homemade food, if they wanted that they'd stay at home. The question is what homemade, the buzzword, is a stand in for, and the answer is a little bit complicated.
Americans dine out more frequently than any other people in the history of the world. We like professionally prepared food and many of us don't know how to cook. On the other hand the archetype of the American family is of one that dines at home in a neat little nuclear unit, consuming food that Mom whipped up with a little elbow grease and a whole lot of love. Nowadays mom's working too hard to have hours to spend cooking, and there'd be nobody there to eat it anyway since dad lives in Lake Tahoe with his new girlfriend, Kathy's anorexic like 80% of the women on television, and Michael thinks meatloaf tastes like dog shit and isn't afraid to say it. So they go out to eat, or order in, and they get fat (except for Kathy) and get used to eating food that tastes virtually the same every time they eat it and develop all sorts of other unhealthy behaviors. On the other hand there's still that dream out there of the home cooked meal and the happy family and the rest of a mythical past that was never nearly as good as people pretend it was. (50's fantasies never really reference the African American maid who was forced to clean houses because economic opportunities for her were somewhere between diddly and squat, nor the fact that if dad got drunk at bowling and beat the crap out of mom the police would stay out of what was termed a "Family affair.")
So Olive Garden tries to ease guilty consciences by offering "Homemade Soups." See, it's just like eating at home, only you're not at home you're at a chain restaurant, and the waitress hates you because you're probably lousy tippers, and the portions are likely too big. This is the path America seems to be taking, life's experiences being watered down to marketing phrases. Images of the overrated past trotted out and paraded in front of us as small lies for us to consume at a reasonable mark-up.
Homemade has other connotations too, of course. It's a little upscale, not because home cooking is something the rich traditionally do but because having someone else cook for you in their home implies economic power over them, and there's the whole bed and breakfast scene where little old ladies really do slave over a hot stove serving family recipes and nostalgia to slightly balding gay men and heterosexual couples who read Town & Country. It personalizes an interaction that's frighteningly impersonal. Food used to be one of the most intimate aspects of life, with families eating together and friendships forged over the "breaking of bread" (Serrated knives being for pussies). Now what you eat is decided by some pudgy white guy in corporate who has a report telling him that orange glazes move 3% more product than white wine sauces, and that having 11 entrees gives people a sufficient feeling of choice without overwhelming them. It's big business, huge business, and like all big business it comes down to numbers. What you think of as a nice plate of Spaghetti is actually a $3.07 profit margin, give or take based on local overhead and the price of tomatoes this week. Your waiter sees you as 15% of what you order, 20% if she flashes some tit, and your stomach sees it as 1200 calories from carbohydrates. Numbers.
Calling something homemade is a way of whitewashing what the American eating experience has become. A numbers game. An economic activity not much different from filling up the gas tank or buying new ink for your printer. Corporations desperately want us to forget that they are, in fact, profit motivated corporations. While the commodification of the dining experience may not be a bad thing, the fact that we're so desperate to cover it up certainly says something. People still want to believe that back there in the kitchen grandma Cecilia is cooking their soup with thoughts of how much she loves them running through her head. She's not. Your cook's name is Paco. He makes $11.94 an hour, and he doesn't give a fuck whether you like the damn soup or not, just that you don't send it back.