Because everything is terrible if it isn't on Steam!
It's not really that big of a deal.
Considering I have >100 games on steam, and all my friends are on steam I would rather not switch just to play a few other games. EA is going to lose a ton of revenue since pretty much everything is sold on steam. Will be running like 7 interfaces on one game.
Also, it is a big deal. EA won't let you download your game after a year of buying it with origin.
And you may want to read the origin TOS.
You agree that EA may collect, use, store and transmit technical and related information that identifies your computer (including the Internet Protocol 37683v1 Address), operating system, Application usage (including but not limited to successful installation and/or removal), software, software usage and peripheral hardware, that may be gathered periodically to facilitate the provision of software updates, dynamically served content, product support and other services to you, including online services. EA may also use this information combined with personal information for marketing purposes and to improve our products and services. We may also share that data with our third party service providers in a form that does not personally identify you. IF YOU DO NOT WANT EA TO COLLECT, USE, STORE, TRANSMIT OR DISPLAY THE DATA DESCRIBED IN THIS SECTION, PLEASE DO NOT INSTALL OR USE THE APPLICATION.
I guess EA doesn't want PC sales.