The blessing we would make on oil is Borei Shemen Areiv. Rabbi Yehuda would say Borei Shemen Artzeinu because Eretz Yisroel was extra special to him.

Since when can people just make up their own brachot?

No one would now, but as recently as a thousand years ago new berachos were introduced (e.g., she'asani kirtzono).

just say it, Shim

Look at the Beit Yoseph to siman 46 in Orach Chaim. He discusses post-talmud berachot.
In any event, R. Yehudah was Chazal. What he does by definition is OK. Or are you bothered because he's not one of anshei kenesset ha-gedolah and we are told that they formulated all the berachot?

It just seems funny to me that he can/would do that. Are there any other examples in shas where someone made up their own bracha?

How about the berachah on meat, "...borei minei nefashot". It's in the Yerushalmi Berachot 6:1 (45a).

Actually, this is R' Yehuda l'shitaso. He's the same tanna who holds (at the beginning of the 6th perek) that on certain vegetables, one would make the bracha "borei minei desha'im"; and, he's also the one who opines (beginning of the 9th perek) that upon seeing the Mediterranean Sea (or Atlantic Ocean, depending on which pshat in the Gemara), one makes the bracha of "Baruch...she'asa es hayam hagadol". Rabbi Yehuda, it would seem, holds in general that one should make the most specific bracha possible. "Chayav adam l'varech me'ein birchosav".

I take this back. Ours is said by the amora, Rav Yehuda, while the others are the words of Rabbi Yehuda, the tanna.

However, it still is noteworthy that Rav Yehuda seems, throughout Shas, to be the quintessential anti-Zionist at the time of the Gemara. It is but a few blatt earlier that this same Rav Yehuda was scaring the living daylights out of anybody who wanted to go learn in Eretz Yisroel. (See also Kesubos 110b, "כל העולה מבבל לארץ ישראל עובר בעשה"; Gittin 6b, "הא איהו דשלח ליה לרב יהודה בני אדם העולין משם לכאן הן קיימו בעצמן ויתנו את הילד בזונה והילדה מכרו ביין וישתו"; as well as many, many other places.) We clearly see that, despite his strong love for Eretz Yisroel, Rav Yehuda did not allow his feelings to interfere with his serving Hashem strictly according to halacha.

R. Zeira wasn't serving God strictly according to halachah? Because you know, even according to the VaYoel Moshe, we pasken according to R. Zeira and not R. Yehuda in that sugya in Ketubot.

Nce to see we're catching up.

No, what I meant was that Rav Yehuda paskened the halacha in an objective manner, independent of his emotions. That is not to say that we necessarily pasken like him (as you said, we do not); rather that he learned the halacha exactly the way he understood it or had been mekabel it from his rebbeim, without letting his deep and profound love for Eretz Yisroel hinder him from fulfilling--l'shitaso--the will of Hashem.