Viacom will have no doubt decided to launch the Paramount Channel based on their success with Spike and Channel 5 - also makes sense from a business and viewer perspective.
Putting it on Pay TV would strengthen its content, but would it really perform to the expectations of Viacom? Surely they now see FTA as a more feasible market to invest in.
As for Sony - their general entertainment Sony Channel has not done them favours on a paywall; and I dare say that the Sony Movie Channel is doing much better than it did as a Sky-only channel. For the latter it was a long term plan of consolidation.
As per my other post, from the perspective of some viewers with Freeview/Freesat I get it. Not from a business perspective, they have missed an opportunity to bolster their Pay TV network in the UK with a new channel. The answer is to invest in both markets, with free channels like Spike and pay channels like Comedy Central.
As for the Sony Channel, the problem is mainly due to a lack of enough quality content. They have a very well known premium brand, and the channel is on Sky, Virgin Media, BT and TalkTalk. However, they have failed to invest in enough quality content to be able to rival the likes of Universal, Fox, W, Alibi, Syfy, Comedy Central, MTV etc. They also have poor
EPG slots which doesn't help.
Sony Movie Channel is rating better than when it was only on Sky, but that's because it is now available to so many more people via Freeview, Virgin Media, BT and TalkTalk. It would have been better to keep Movie Mix as their basic free movie channel and add it to Freesat as well as Freeview, and make Sony Movie Channel a premium movie channel and add it to Virgin Media, BT and TalkTalk as well as Sky. A premium HD channel would be far more befitting of the Sony brand.