Isn't about a user cracking the code, to apply a change on the network then more than 50% of the nodes should run with that change.
This is completely wrong. The set of consensus rules is not manipulated by the majority. When you're running a node, you're
obeying these rules in order for your node to be considered as a "Bitcoin Node". A change in the consensus rules means that you're not
obeying, which also means that you're not following the bitcoin blockchain. These rules were set by Satoshi and they can't change just because the majority says so.
In other words, if the majority of nodes decide to change one of these rules, they instantly stop being the majority.