Why can't they give us our tv EVERYWHERE, easily?

I fired up my XBOX 360, since there is STILL no support on XBOX ONE for the following:
- HBO GO
- Showtime Anytime
- Dozens of others

I was able to run & authenticate HBO GO easily, but Showtime Anytime wasn't so easy.

First, since I tried authenticating on the iPad, the site assumed (incorrectly) that I would much prefer the "Showtime Anytime" App.  I would not.  My TV screen is considerably larger than that of my iPad.

So I switched over to the MacBook Air. Safari kept saying "The Primary Account holder for this account must register for Showtime Anytime first."  So I switched to Firefox.  Same thing.  Turned to the Windows desktop.  Same thing.

I've been a Showtime subscriber for nearly two decades.  Why can't "they" just give good service?