The Great Pharmaust FDA ODD Approval Sweepstake, page-137

I think to approve it before the 90 days in full has expired, would open the FDA up to accusations of favoritism also. Like you say, it's a regulated process. There are probably dozens, if not hundreds of companies that want the FDA to approve their drugs also. If you come in early on one drug approval, then I'm pretty sure other companies would start screaming "why wasn't our approval early too!".

Like you mention, that other company which had to make a resubmission, they had to wait 6 months from initial application to approval date - and the FDA went down to the last day of that 6 months before issuing a Complete Response Letter requiring some minor amendments. These items could have easily been raised and addressed well before the end of the 6 months, but the FDA didn't care for that it seems.

The FDA is a regulated, government bureaucracy - not a business that has practical business outcomes front and center guiding its actions.