The answer to this question lies within the true MEANING of the Feast itself.
Leviticus 23:33-43 describes the Feast of Tabernacles. Verses 42 & 43 disclose the basic concept upon which God was building when He proclaimed this Feast: 42 " 'You shall dwell in booths for seven days. All who are native Israelites shall dwell in booths, 43 that your generations may know that I made the children of Israel dwell in booths when I brought them out of the land of Egypt: I am the LORD your God.’ "
The Scriptures tell us that God ALSO had a "booth" (temporary dwelling):
Exodus 25:8 8 And let them make Me a sanctuary, that I may dwell among them.
Exodus 29:42 This shall be a continual burnt offering throughout your generations at the door of the tabernacle of meeting before the LORD, where I will meet you to speak with you. 43 And there I will meet with the children of Israel, and the tabernacle shall be sanctified by My glory. 44 So I will consecrate the tabernacle of meeting and the altar. I will also consecrate both Aaron and his sons to minister to Me as priests. 45 I will dwell among the children of Israel and will be their God. 46 And they shall know that I am the LORD their God, who brought them up out of the land of Egypt, that I may dwell among them. I am the LORD their God.
Now see the pattern in history that tells us about the future: we know from the Scriptures that when the Jewish people made an encampment during the Exodus, they put up their booths (tents) according to their Tribes, with Levi being the closest to God's "booth" or "tabernacle." These booths actually circled around God's own "booth." This was a foreshadow of what would occur during the Messianic Age, when "He who sits on the throne will dwell among them" (Rev. 7:15b; see also Isaiah 4:4-6). The most dramatic declaration regarding God dwelling among them during the Messianic Age is found here:
Ezekiel 43:7 And He said to me, “Son of man, this is the place of My throne and the place of the soles of My feet, where I will dwell in the midst of the children of Israel forever. No more shall the house of Israel defile My holy name, they nor their kings, by their harlotry or with the carcasses of their kings on their high places."
And so, we see that the TRUE meaning of the Feast of Tabernacles looks forward in time to when God will once again dwell among His people -- but this time, He will never leave as He did before. But while the Feast of Tabernacles is celebrated today in ANTICIPATION of the Messianic Age, DURING that Age it will be celebrated in thankfulness that God fulfilled His promise and now dwells among the people, who are "encamped" around Him. Therefore, if anyone were to refuse to celebrate the Feast, it is tantamount to denying that God dwells in Jerusalem.
It is also interesting to note that the Scriptures suggest Yeshua was born on the first day of the Feast of Tabernacles.