Tosfos in the Gemarah Sota 10b writes that being מלבין את פני חבירו is a sin that one should rather give his life up for. Therefore, in the case of the Ben Sorer U'Moreh, why do we make such a big deal out of making sure that his death is public? Is this not going against embarrassing someone?
במקום שיש חילול השם - אין חולקין כבוד לרב - "In an instance where there is desecration of G-d's name, we don't allot honor to a Rabbi". Humans who have debased themselves to the levels of animals (including the ben sorer umoreh) and have committed capital crimes, are judged by the Torah as having forfeited, to some degree, their right to a certain level of human dignity. (It's also worth noting that according to one opinion in the gemara, the laws of the ben sorer umoreh are theoretical ones that teach a lesson, but were never and will never actually be practiced.) Regardless, the only absolute in the Torah is, arguably, the ban on idolatry. All other values have scenarios where they are trumped by other competing values.
Double's right, this is true for all executions, and it's worse for Ben SU"M because he's executed for "something he didn't do, but for something he might become" as the Gemmorah says.
The point of public executions is explicitly commanded in the Torah so there's no much what we can do against. We can resolve it in different ways but the decree of the Torah remains:
וְהָאִישׁ אֲשֶׁר־יַעֲשֶׂה בְזָדוֹן לְבִלְתִּי שְׁמֹעַ אֶל־הַכֹּהֵן הָעֹמֵד לְשָׁרֶת שָׁם אֶת־ה"א אוֹ אֶל־הַשֹּׁפֵט וּמֵת הָאִישׁ הַהוּא וּבִעַרְתָּ הָרָע מִיִּשְׂרָאֵל׃
וְכָל־הָעָם יִשְׁמְעוּ וְיִרָאוּ וְלֹא יְזִידוּן עוֹד׃
Should a man act presumptuously ... that man shall die. Thus you will sweep out evil from Israel: And all the people will hear and be afraid and will not act presumptuously again.
THere are two ways of explaining it:
The public execution IS a humiliation: then it can be seen as a part of the punishment. As we hold that a humiliation as the suffer can ease one's punishment.
The public execution IS not considered a humiliation by the Torah (de-jure). So the question is closed.