Weapons weren't the most difficult thing to produce or procure, and many tools and farm implements could be used as such, which likely formed the principle armament of most peasant revolts in China and many other parts of the world. Shields were only slightly more difficult, as they're not something everyone already has, but easy enough to make. Armor was a different matter, as it generally required some skill to produce and fit to the wearer: more material than a weapon, more skill to create, and more time to produce. Organization was another big issue, since drilling and training even a modest sized formation pretty much indicates to everyone in the region that you're preparing to create your own army, and there's no shortage of information leaks when you've got several thousand participants. If you don't already have weapons and armor, there's a problem, because you can expect a visit rather shortly from a whole lot of the regional or national authorities and their well-armed assistants once they hear about it.
A fine example of weapons and armor being an issue is the ascendance of Rome. Veii was the local Etruscan power in the region, and Rome was the local Latin power, neither being strong enough to completely conquer the other without the assistance of their kin in the surrounding cities, yet not being supported when they were in danger of becoming too powerful within their own alliance. Veii (and the Etruscan League in general) suffered a massive defeat against the Greek states in the southern tip of Italy, losing virtually their entire armies when the fully laden transport fleet was sunk with few survivors. The manpower could be replaced, and weapons of varying quality could be gathered or made quickly enough, but replacing all of the chain mail and other armor was the work of at least a generation. Rome seized the opportunity, sieging Veii for several years until it fell.
The American Revolution was another example of the difficulty in supplying weapons. The colonists were unable to mount any serious revolt because skilled gunsmiths were heavily limited and regulated by British law. At some point, a couple of aspiring colonial entrepreneurs met in a coffee shop in Vienna and discussed the situation. Alexander Hamilton had just toured an innovative tackle block factory in England earlier on the trip, where each craftsman only needed to know one step of the operation, then passed the work on to the next person on the assembly line. Hamilton reasoned "We CAN make our own guns", WITHOUT the normally required number of skilled craftsmen, and a revolution was born. The moral being, supplying your idle thinkers with too much coffee can lead to political problems.