Jewish Catch 22

I hate second day of Yom Tov. It's stupid, outdated, and I've never been given a good reason for observing it. The excuse of minhag avoseichem b'yedeichem is just that, an excuse. It was some kind of tax placed on people living outside of Eretz Yisrael.

The concept of celebrating second day of Yom Tov took shape around the time of the building of the second Temple in Jerusalem. And the idea, back then, had a semi-good reason. Basically, since there was no OFFICIAL set calendar, though the Sanhedrin (Jewish idea a supreme court) DID know exactly when the new month started without needing witnesses to come in and report they had seen the birth of a new moon, those outside of Israel lived too far away to get the news of the start of the new month before the holidays started (during months when there are holidays). So, JUST IN CASE, those outside of Israel celebrated two days of the holiday instead of one.

All good and fine. Silly. But fine.

Then, about somewhere around the fourth of fifth century CE, Hillel Hakatan set the calendar. Forever. He used a nineteen year cycle that includes seven leap years and absolutely, in stone, sets the calendar, when the new month starts, and when every single holiday occurs. Gone completely was the need to keep Yom Tov Sheni.

Yet the rabbis in Israel decided those outside of Israel should continue to observe the second day because of the above-mentioned "minhag avoseichem b'yedeichem" - keeping the customs of our forefathers.

Wonderful. There are so many holes in this. First, as I mentioned, this was basically a tax on the rest of us. Second, it's nonsense. Forcing us to keep the CUSTOM of the second day actually forces us to NOT keep actual Mitzvos D'ORAISA - actual TORAH MITZVOS, not just outdated customs. It also forces us to make unnecessary brachot.

I discuss more about second day of Yom Tov here, and here. Some entries are repeated in both links.

So, here's my Catch 22. I'd very much like to go to my rabbi and tell him that if I am forced to continue observing second day of Yom Tov, I will cease to be Orthodox altogether. I would like to ask him if it's really worth hinging my entire observance on a completely outdated custom, simply a custom, not even an actual mitzvah d'rabbanon.

Problem is, and here's the Catch, is if I stop observing second day, I will no longer BE considered Orthodox, even though I'd be keeping every other mitzvah and halacha!

So, which is it?