User blog comment:Arbington/The Next Cycle/@comment-2094653-20120803225240/@comment-1221773-20120804053626

Organic starships have to discharge static electricity buildup from their drive cores roughly every 50 hours by grounding on a planet or entering a planet's magnetic field, otherwise the buildup incinerates the ship's crew, destroys its electronic systems, and even melts parts of the ship itself. Heavier or faster ships have to discharge more frequently. With current FTL technology, it would take organics six years just to reach the Reapers.

There are probably additional issues which any Reaper hunting expedition would also have to account for. Off the top of my head, how do you locate Reaper central in a literal middle of nowhere, and how do you prepare an organic armada for a round-trip journey that could last as long as 12 years? The way I see it, the races of the next cycle would need to have technological parity with the Reapers for such a gambit to succeed, and by then it might be simpler to wait for the Reapers to return to the galaxy and ambush them.

Now all of that would be moot if organics could harness the Citadel relay for themselves, but doing that could wake up the Reapers and spoil a surprise attack. And surprise or not, if the organic attack fails, the Reapers would be aware of the threat organics had become and immediately head to the galaxy to purge them anyway.