The traditional exposition of the events at Kivroth HaTa'avah is that they wre not "good" behavior on the part the Jewish people in the desert. Here and Here
However, the Baal Shem Tov explains it with a teaching that the goal of Divine Service is killing all desire.
Sources:
Kehos Chumash
http://www.chabad.org/media/pdf/293/TLKr2932217.pdf p.40
quoting
Degel Machane Ephraim
http://www.hebrewbooks.org/3723 80a (p.165 in pdf)
Sichos 5719
דף הבית > ספרי כ"ק אדמו"ר > תורת מנחם > – כו – שנת תשי"ט – חלק שלישי > בס"ד. ש"פ מטות-מסעי, מבה"ח מנחם-אב, ה'תשי"ט > 153
As an aside, not only this 13th journey of the 42 but all the forty-two journeys have been expounded upon as have meaning to our own travels in life. Travel can be a metaphor for jurney thorugh life. See the Tales of the Baal Shem Tov volume 5, p.194 where the Baal Shem Tov tells one of his chassidim his whole life story as a parable of travels.
The concept of killing all desire has been explicated in later chassidic literature. Many chassidic commentaries (Shem MiShmuel, Imre Yosef, Kehilas Yaakov/Yasharesh Yaakov ... ) elaborate some nuances of this concept. Put simply it is clear enough: one should strive to get to a that level of connection to HaShem where earthly desires die and no longer block one's spiritual ascent. The Likutei Levi Yitzhak (Igros p.12) speaks about this in the context of different types of spiritual deaths.
This approach comes from an early Kabbalistic work called "Brit Menucha" of which there is a nice clear new edition published as well as an "attempt" (which I have not seen) to translate it into English.
http://www.chabad.org/theJewishWoman/article_cdo/aid/458381/jewish/Books-that-Speak.htm
http://www.amazon.com/Brit-Menucha-Avraham-Yitzchak-Granada/dp/1897352018
This Bris Menuchat is a rather opaque, other-worldly sefer (which has mostly been quoted by later authors in regard to the proper proununciation of HaShem's name). To one who has ever looked into this obscure and highly stylized sefer it is truly a wonder that a practical lesson from it can be taught.
However, a slightly different interpretation of the same passage in Brit Menucha is given in classical mussar sefarim preceding the Baal Shem Tov: Reshis Chochmah (Shar HaYirah 2), Yaaros Dvash, Emek HaMelech and Shnei Luchos HaBris (Masechtas Shavuos). They all reference the sefer and speak about experiencing the source of Chochmah leading one to a nullified existence on the worldly plane.
Although firmly based in Chassidus, the approach of killing all desire has not been adopted in later generations. It is not in accord with the popular version of the commonly taught theology of Chabad Chassidus (http://www.amazon.com/Heaven-Earth-Reflections-Schneerson-Lubavitcher/dp/0826604889) or for that matter any mainstream chassidus. Indeed, the Baal Shem Tov's own student, Toldos Yaakov Yosef (Parashas Metzora I) points this out while explaining of the famous episode Four who entered Paradise and states that only Rebbe Akiva achieved success in applying this principle as opposed to Ben Azzai and Ben Zoma who were harmed by it.