Okay so i just got on today, and decided to check out my skele XP farm, turns out it wasnt spawning, so i broke it, it in turn gave me a mob egg, i threw it down and all i got was one skeleton, and my mob egg was gone, why is this, getting a mob egg in turn for a spawner and only being able to spawn one of the said mob is completely unfair, so, i was wondering, why is this so?

Because mob eggs only ever give one mob. There was recently a change in plugins that we used to manage spawners (since you don't get anything for breaking them in vanilla minecraft), and the updates/details were outlined here. Though, if you got an egg, you broke the spawner with a non-silk-touch pick, and even with the previous plugin, that would have only given you a default spawner (pig), which would have destroyed the skele spawner anyways.

but is there a way of making it so mob eggs spawn a infinite amount of said mob like in creative?

Mob eggs do not spawn an infinte amount in creative, you have an infinite number of eggs (as with all blocks).