Franco has been discussed at length above. But for the record, he was signed in 2010. Montgomery/Amaro/Manuel/Noworyta/Wolever.
Cody Asche was a fourth-round draft pick - the scouting consensus was that he was not going to be a good major-leaguer. A lot of Phillies fans convinced themselves otherwise ("He's outperformed!"). The scouts were correct. Asche's career has been more-or-less as projected by the professionals.
Nick Williams was a second round pick (of the Rangers, not the Phillies). He was available in trade because his offensive game had holes - lack of plate discipline. The Phillies didn't make that disappear. Williams was acquired in July 2015 - by Gillick/Amaro. (MacPhail had been hired as a special assistant one month prior. Klentak was in California.)
Andrew Knapp was a second-round pick of the Phillies, in 2013. At the time, Johnny Almaraz was an employee of the Atlanta Braves. Fans here saw this as a "safe" pick, but nobody got excited about it.
So, where do the fan expectations, which wind up unmet, come from? We build our hopes around these guys...why?
You can blame the Phils' marketing department, for promoting iffy prospects as saviors. You can blame the Philly media for rhapsodizing about "up and coming" minor leaguers. At the end of the day, though, I have to wonder if a lot of it isn't on the fans - for seeing and believing what they want to see, rather than what's really there, for gullibly accepting what PR types and press hacks tell them.
The Phillies' PR types are going to promote whatever players they have to promote, regardless of whether they're really any good. Rico Brogna? Jeff Stone? Glenn-bo? But that's their job. Seeing through advertising hype (in our caveat emptor society) is the responsibility of the consumer - advertisers of all products spin and deceive - it's what they're trained to do, it's what gets them rewarded. If you believe it - whether that's "Maikel Franco will save the Phillies" or "the Ginsu is a great knife," or "the Popeil Pocket Fisherman is all a fisherman needs" - well, that's on you.