The hit was mandatory for firing accuracy in vanilla already.
I just made sure it applies to everything... e.g. also to throwing accuracy.
Btw. only a hit is required, no need to do any damage.
Psi is no different, it's just not possible to miss with a psi attack.
This mechanic is the corest of the core... xcom would not be xcom without it... I just can't do this without betraying everything I believe in. Sorry.
If there is a problem with training rookies, there are solutions to make training easier for you:
1. OXCE+ offers a training base facility, where firing accuracy can be trained, among many other things. It's also configurable how quickly and until what limit. Easy and convenient.
2. Or, as the game progresses, you could start hiring rookies with better starting accuracy. That is easily moddable too.
EDIT: let me give you an example what would happen if I allowed experience gain from shots in the air:
- find an alien base
- build your base next to it
- hire a craft, max number of rookies and pistols for everyone
- go to the alien base, fire 11 times (or even less, just repeat more times) into the air in the first turn
- abort mission, gain experience
- repeat from the beginning until everyone is fully trained with no risk
This way you could train absolute rookies into superstars in a matter of several game hours... how should I allow that with a clear conscience?