I can see where you're coming from, mainly because now he can't share Shielding with his teammates, friends, or allies.
On the other hand, this is a story. Just because I would want him to be able to share Shielding if I was a Matoran who needed his protection doesn't mean story writers should interfere with the realism of the story to make it happen. If so, nothing bad would ever happen and we'd have basically no story at all. I wouldn't have wanted Makuta to take over either (while evil anyways ) if I was a Matoran.
Realistically there are trade-offs, and while Shielding is cool, there's always other things he could have that would help in other situations that he never had and you probably haven't been really hoping he would. Since he's now already far more powerful than most others, it makes sense there should be at least some kind of cost to that.
What interests me is more what he could do to make up for it. Because then we get to use our brains and imagination and it gets fun.
One obvious thing is, say a Matoran is in the path of a projectile. He could leap in front, using his normal Hau. In that situation, protecting himself equals protecting the Matoran because the projectile would be forced to bounce away.