I don't see any demonizing, Torts gave Frost and Farabee plenty of chances to prove themselves.
Farabee flatlined, maybe b/c he adjusted quickly with his smarts but over time his physical limitations won out, he never filled out and isn't that strong, he has average speed, average shot though good hands near the net, but lacks the anchor for the dirty area. He's better than he's shown this season (Sh% is half his norm), but never developed into a reliable 2LW. Good scorer who needs to play with better players.
Same with Frost, who had his best season two years ago (under Torts) but hasn't been able to build upon it. He just lacks "it," he's good in open ice but simply isn't a great playmaker in the "half court" or on the PP. Very good but not great speed and he doesn't play as fast as his timed speed. He's never been able to add functional strength and gets knocked off the puck too easily. He's responsible defensively but depends on his stick. A dependable middle six center who was never able to develop into a 2C.
They don't fit the Flyers style, which is fast and physical down the middle (Cates, Poehling, Jett), allowing a mix of size and skill at wing (TK, Brink, Michkov and Tippett, Foerster). Which suggests they're looking for another center in trade/the draft who fits their prototype - full size, above average speed, high IQ, two way player.
This move suggests Briere is ready for a fire sale this spring, if they thought they could stay in the playoff race they'd have waited until June to move Frost.