A full refill sort of the defeats the purpose of having to learn which weapons do what. If there's no consequence to running out, why even have a meter at all?
For me it was the complete opposite. Because the weapons were limited (and I was never sure if I would be able to refill them when I needed to) I never used them until I was on a boss. It wasn't until Mega Man 8 that I felt comfortable doing so, and it's my favourite one by far because of that (haven't played 9, 10, 11 yet). Don't knock it 'til you try it.