It's similar to giving special status to Apple by not penalizing their China-based manufacturing, then hoping that OTHER not-too-big-to-fail companies will be able to do what Apple couldn't (manufacture at a competitively cheap price onshore) while additionally facing this unfair competition.
It seems it'd be more effective to have incremental (based on % domestic manufacture & labor) rewards/penalties for those making changes rather than carve-outs for those too-big-to-fail and making competition even harder for those you are trying to incentivize.
Also, never mind manufacturing - how about addressing IT offhsoring, which is something far easier for US companies to change if incentivized/penalized appropriately. Is it really domestic clothing sweatshops that we want to encourage, not domestic high-tech industry with well paying jobs, paying high taxes, and helping retain onshore talent in an area of importance to national security?