From my brief knowledge of servers banning items, they usually don't use things like MineTweaker, instead they make it so you can't right-click with the item or place it or have it be in your inventory or whatever. I don't mean to offend, but it's kinda impossible to stop server plugins and it ends up just being a pain for everyone else. Actually, MineTweaker and other recipe editors is usually used for custom modpacks like Magic Farm or Blood 'N Bones where progression is edited.One, it is because more often than not, items are disabled based on the opinion (and often a hasty decision rather than a well-researched one) of a select few people, or even one person. This then leads to many "server admin takes one glance in creative mode->bans half of mod either directly or by banning prerequisite" type situations. Additionally, even if the issue is allegedly one of balance, I do not buy for a second that all people on a server - especially a large server - match opinions on what is balanced. The general rule is, as I see it, "if you like it, use it. If you think it makes the game too easy and not fun, do not use it". Unless it was something that gave a huge competitive advantage you cannot legitimately claim that you have the right to tell others that they cannot have something because you do not want to use it yourself.
Two, it is depressingly common for items to be banned not because admins dislike them, but with the intention of putting them behind cash barriers ("you must be a member of $50/mo donators to place this"). This is essentially monetizing a mod that you did not create, not to mention incredibly dickish. Even if you do not do this yourself, many people do, and the rules must be enforced equally or it would be tremendously unfair.
As for the server monetization deal? In general, just avoid those servers. Best way of getting rid of them is choking them out.