To be honest I'm not sure that Tachyon Beam draining a thousand shield per second from players in PVP would be a bad thing. For a science ship, its officer abilities are its weapons. Having an ability that can remove meaningful amounts of shields regardless of the target's defense and shield hardness would shut down all those complaints about tanking escorts and unkillable cruisers, no? Let's not forget that tachyon beam does no hull damage of any kind and it's a boff ability with less than 100% up time, unlike the dual-cannon-toting lulzscorts.
But yeah. Tachyon beam is worse than useless in PVE. When I made my science character I was excited to see what TachB could do for a specced character flying a custom built drain ship. My excitement did not last long. Same story with Delta Flyers as combat pets.
Tachyon beam? More like tickling beam.
In defense of drain builds, ES2 and ES3 cycling with a TR2 can still make a tac cube/gateway/donatra have MUUUUUCH less bite.