Non action is also political. The say they don't want to appear political, but by not acting, they are. Politics is everywhere. You can't get away from it. Better to be consistent with your policies and apply them the same to everyone.
I agree with you 100%.

they can reopen an investigation into hillary weeks before the election but refuse to open an investigation into donald after he lost an election and tried to overturn the election.

and yet republicans will still complain the doj has been weaponized against them.

This is tough since it's a part of the executive branch and as a result not wholly independent of who is in office. It'd be nice to have a wholly impartial investigation organization, but even then it's still staffed with humans, all with their own virtues and vices, perspectives and prejudices.

Same thing with Comey. Such utter bullshit.

I guess in any kind of properly-functioning government, the FBI would have been acting in the wake of (and with the support of) some decisive political response by Congress. There's no sane version of reality where half of our elected reps should watch a direct attack on themselves and the core of our country, then huddle up and decide to play it off as nothing in order to preserve their power, and yet here we are. They have signaled as a group that they will not support any response to anything surrounding Jan 6, will reject factual information about it as needed, and will use their position to harm anyone who attempts to act on it. This doesn't excuse the FBI's lack of action, but it has definitely yanked a critical pillar of support out from under their work. They should not be in this position, where even doing their duty in the most objective way possible is considered a hostile act by a portion of Congress.