SCB doesn't lower your DPS or make you face your friend to help him. While using SCB you can fight but to heal wing mate you can't deal damage to enemy. Also for lasers you need at least 2 ships and not one. Also healing lasers make teamwork more important and that is always good thing. Also SCB heal you a lot and fast. Healing lasers won't have same effect. Max healing will be same amount than one same size and rating beam laser do damage (this make sense). So to heal as much as other ship deal damage you need to have same amount of these healing lasers than attacker instead of lasers that do damage. So healer can't be effective at dealing damage. So healer can't defend himself and can be destroyed first.
I am mostly thinking here for in between fights. Alone, you have the choice to use your limited SCB+heatsink ammo, or wait 10 minutes. In a wing, some Anaconda can spare a few hardpoints for these healing beams and top you up quickly (much more quickly than shield regeneration for sure). This downtime in between is just boring, and I would find it very unfair if wings can skip most of it while a lone ship still has their 10 minute (or more) shield regeneration time to endure.