If someone finds themselves chasing whatever streaming service has The Office, maybe it's worth dropping the $300 or whatever for everything on iTunes.
The choice people have now is to pay $200/month at the big box store for a pre-loaded shopping cart of channels, with maximum ads, or to pay $10/month, a dozen different times, to go all over town picking up one channel at a time from little niche stores that only sell that channel, some that come with ads, and some that don't.
Multiple streaming marketplaces that all have the capability to connect all the same vendors to the marketplace customers would satisfy the consumer demand. But right now, everybody is taking their content back to put in their factory-direct exclusive content stores.
In the physical goods world, someone could buy at the factory store, ship at their own expense to the common marketplace, and resell at their own risk with a markup. Consumers would pay the markup as the cost of convenience. But in the digital world, you can't necessarily resell anything, even if you bought the right to use it yourself.
So we have still never received what we have repeatedly asked for. Netflix-by-shipped-disks approached it, because it could buy the disks at retail, and mail them around at its own expense, without getting any further permission. Netflix-by-download cannot, because the streaming rights are revocable, time-limited, and subject to constant haggling and renegotiation by the sellers every time the contracts expire.
Fragmentation is not ordering from the a la carte menu; it's getting fries from McDonald's, a shake from Wendys, sandwich bread from Panera, meat from Arbys, lettuce from Taco Bell, tomato from Subway, and spending three hours in the car just to get your lunch. A la carte means you can order your whole lunch at one place, getting just what you want, and not getting something that you don't want means you pay less overall for your meal.