Ya'akov's Tnai

I've always been bothered by the Tnai that Ya'akov makes at the beginning of last week's parsha (Vayetze).
Right after the famous dream with the ladder, Ya'akov makes the following "Deal" with G-d:

בראשית כח כ-כ"א
וַיִּדַּר יַעֲקֹב נֶדֶר לֵאמֹר אִם יִהְיֶה אֱלֹהִים עִמָּדִי וּשְׁמָרַנִי בַּדֶּרֶךְ הַזֶּה אֲשֶׁר אָנֹכִי הוֹלֵךְ וְנָתַן לִי לֶחֶם לֶאֱכֹל וּבֶגֶד לִלְבֹּשׁ. וְשַׁבְתִּי בְשָׁלוֹם אֶל בֵּית אָבִי וְהָיָה יְהוָה לִי לֵאלֹהִים

Jacob made a vow. 'If God will be with me,' he said, 'if He will protect me on the journey that I am taking, if He gives me bread to eat and clothing to wear,
and if I return in peace to my father's house, then I will dedicate myself totally to God.

To me this Tnai always sounded very superficial, similar to "If G-d helps me find a parking spot then I'll got to shul on Shabbat", or "I'll wear Tefilin every day if G-d helps me get this job".

This attitude seems beneath Ya'akov Aveinu, surely his commitment to HaShem is unconditional. What does he mean "IF God will protect me" - and what if he doesn't, does Ya'akov imply that he would be less committed to serving G-d?

I think a partial answer can be found in yesterday's Daf - Kiddushin 61A

דף סא, א משנה ר' מאיר אומר כל תנאי שאינו כתנאי בני גד ובני ראובן אינו תנאי שנאמר (במדבר לב) ויאמר אליהם אם יעברו בני גד ובני ראובן וכתיב ואם לא יעברו חלוצים רבי חנינא בן גמליאל אומר צריך הדבר לאומרו שאלמלא כן יש במשמע שאפי' בארץ כנען לא ינחלו:

Rabbi Meir says that any Tnai that isn't like the Tnai of Bnei Gad and Bnei Reuven isn't a Tnai....

Rabbi Meir's opinion is that a Tnai is only valid if you make a "Double Tnai" - e.g., "I will do X if you will do Y; If you do NOT do Y, I will not do X".
Without the second half, Rabbi Meir holds that it is not a Tnai, in effect what you are saying is "I will do X if you will do Y, however if you do NOT do Y, I may do X anyway"

Now Ya'akov's commitment makes sense according to Rabbi Meir - Ya'akov is asking / praying that HaShem will watch over him during this difficult stage in his life, and he is reminding himself and G-d that he is committed to serving HaShem, however he never made a "Double Tnai" - if HaShem does NOT fulfil that which is asked of him, it does not imply that Ya'akov will be any less of an Eved HaShem.

Comments?