Why did Beit-El not earn a special status, given the prophetic revelations that Yaakov experienced there?
Jerusalem, the site chosen as the eternal "holy place" is the site that represents sacrifice, of giving of oneself for the Almighty, rather than Beit-El – the place where God promised to bless and protect Yaakov. We must focus our attention on our responsibilities to God, our obligation to serve Him to the very best of our ability, rather than on that which God promises to do for us.
We read in Parashat Vayishlach that God revealed Himself to Yaakov in Beit-El upon his return from Charan, just as He had spoke to him there as he fled from Canaan (35:9). The Torah writes that upon concluding this second prophecy, "God ascended from him, at that place where He spoke with him" (35:13). Rashi comments on this verse, "I do not know what this teaches." Rashi saw no reason why the Torah would emphasize that God left Yaakov "at that place where He spoke with him." (See Ramban, Radak and Keli Yakar.)
Rav Moshe Leib Shachor, in his Avnei Shoham, suggests a possible explanation for this emphasis, claiming that the Torah wished to "downplay" the significance of Beit-El as a site of divine revelation. The Torah anticipated that this location, where God had twice appeared to Yaakov at critical junctures in his life, to either promise him protection or predict the emergence of dynasties from his progeny, might one day be looked upon as a shine of sorts. Indeed, when Yerovam ben Nevat led the cessation of the ten northern tribes and established the Kingdom of Israel, he designated Beit-El as one of the new kingdom's religious centers.
Conceivably, the Avnei Shoham speculates, Yerovam succeeded in drawing attention to Beit-El by pointing to its rich prophetic history, as the site where God had appeared to Yaakov. The Torah perhaps sought to dispel this misconception of Beit-El as a holy city comparable with Jerusalem, and therefore emphasized that God left Yaakov at that site. Meaning, once the prophecy concluded, God's presence departed and Beit-El returned to what it had been previously, without obtaining an eternal status as a holy city.
Why, in fact, did Beit-El not earn a special status, given the prophetic revelations that Yaakov experienced there?
It might be suggested that Jerusalem, rather than Beit-El, was selected as the permanent "holy site" of Am Yisrael because of the theme of sacrifice which it embodies. As the Rambam famously writes in Hilkhot Beit Ha-bechira (2:2), the site of the Mikdash in Jerusalem had been designated many centuries earlier as a site for sacrificial offerings. Adam, Kayin, Hevel and Noach all offered sacrifices at this site, and of course it is there where Avraham bound his son Yitzchak upon the altar preparing to offer him as a sacrifice. And at this site King David offered sacrifices to bring an end to the plague that ravaged the country.
Significantly, the site chosen as the eternal "holy place" is the site that represents this theme of sacrifice, of giving of oneself for the Almighty, rather than Beit-El – the place where God promised to bless and protect Yaakov. We must focus our attention on our responsibilities to God, our obligation to serve Him to the very best of our ability, rather than on that which God promises to do for us. It is for this reason, perhaps, that tradition has elevated the status of Jerusalem while downplaying that of Beit-El – because our concern must be, first and foremost, how to best serve the Almighty, rather than how the Almighty can best serve us.