They could have continued with the resources they had and chose not to, Raffi's alternate plan took that into consideration.
The answer was still no to any kind of rescue plan no matter how pared down it was, that was politics plain and simple, Picard even called them on it.
It wasn't a matter of resources alone as more could have been gathered, it was also a question of available time, even so they could have attempted a limited rescue if they had wanted to, the reality is that they didn't want to and it was politically easier not to bother.
I appreciate you don't want to see an Odyssey class but that decision has already been made one way or the other, even if as you say they didn't have the resources to build them at the time, they most certainly did have the resources in the 15 years following the attack on Mars, to think that an attack on a single shipyard would cripple ship building in the entire Federation for a year never mind 15 is ridiculous.
It was only one Shipyard that was hit and your argument might have some sliver of merit if the attack had also been aimed at crippling the gathering of critical resources or the logistics of transporting those resources to where they are needed.
That was not the purpose of the attack, it was to destroy all the Synthetic crews and fool the Federation into banning Synthetic Research, the Federation took the bait.