Black people all over the world incorporate drums into their music. So we dumb for being moved by them huh
Per fans annotations on genius:
The “dumb” here is a Five-Percenter reference, to the 85% of people that are blind to their own divine natures.
As Jay-Z would say:
Do you fools listen to music or do you just skim through it?
Given the religious imagery being used and particularly “blind/dumb” (also the usage of “death” in the next line almost sounding like “deaf”), he’s likely using “dumb” in the biblical sense of “deaf, dumb and blind”, from Exodus 4:11 (the GZA’s favourite kind of rolling papers), meaning those without the ability to speak. Deaf, dumb and blind is also a concept which features in the Five-Percent Nation and as a result, in Wu-Tang’s music.
In this context, he’s saying those who fall under the 85% won’t listen to the lyrics and instead will simply be entertained by the beat