OK.
IF. We find a medium of refining artificial meat to such a degree that it becomes tenable as a infinite food source as derived from Feces.. it will be revolutionary and in fact ESSENTIAL, if we are to ever have long range sustained space flight or sustain the population of Earth for an exceedingly long duration.
However. The scientific discussion that has followed this topic is completely irrelevant up to now as it has no bearing on the actual argument that was started... which was: COULD this become tenable?
Now, the two answers available are either yes... or no..
Taking all factors into account:
The amount of crap needed to feed a third world country for a day would be along the lines of say.... hmmm.... 4756 Krusty's? In short ALOT. Now to do such a thing with the technology we possess now.. we would need a "CRAPLOAD" (see what I did there

) of both money and equipment. As well as technicians and scientists to operate and continuously develop the tech and methods of the process. Now if you were to assign one of these operations to every sewerage farm on planet earth, and build even more in areas which do not possess adequate drainage and STILL MORE scientists and technicians needed to be both trained and educated up to Modern Standards to operate. Your talking QUINTILLIONS! of dollars which we simply do not have. The reform needed would be so drastic it would take both a 1 world government and a nationalist abolition of free choice and currency to achieve.
To speak from the other side however, theoretically and scientifically it is not only possible but in fact essential to have this technology for the very reason penguin pointed it out. We cannot sustain life on earth or long range spaceflight without a renewable source of food... and of course both of those things, SF and Sustainabliity are the two things we need to ensure survival for any long duration.
In short. Both sides have argued a pointless excercise... this technology has to advance to the extent where this can be a simple machine in the home. When this happens. It should be installed on a large scale.. and inherently solve food and feces... Then we move planets.. to several in fact. There goes over population. It is necessary to do that soon... otherwise our race will perish..
Ok Rant Over.