The devs probably never thought players could have the manpower and dedication to completely clear a Titan's control zone, let alone two. Giving Titans the ability to attack was probably the quickest and "cleanest" way to fix this without majorly breaking something else.
Not the most elegant or spectacular solution—there should've been a "last ditch effort" or a "rage state" response to Titans from the beginning. But, being fully honest, from purely a grunts point of view who only knows how to shoot things and how to get past thargoid blockade with 80 souls on board, this war has become a bit boring, more of a background noise instead of a full-on emergency it used to be a year ago. Titans just sitting there doing nothing really isn't appealing to a grunt like me