be nice to have a quicker way to boost energy credits

Though if you want to 'purchase' Energy Credits, you can easily buy 'Master Keys' with 'purchased' C-Points and sell them on the Exchange....

Or Gamma Quadrant Doff packs. They have a better value.

I would imagine Energy Credits purchasable off the C-store would just cause for inflation, which wouldn't help much of anyone in the long run.

More EC flooding into the market will devalue it even more, causing prices to go up. Same reason governments don't just print more money (well most of them :p).