On an ethical level, yes, of course. What they are doing is reprehensible, and if I were in the founding fathers' shoes and was responsible for creating a new country, I'd say "everyone has free speech, but it's illegal to burn the flag". It's disrespectful and downright reprehensible to attack the flag in that manner, disregarding the thousands of men and women who died to defend our freedom. On an ethical level, I'd be fine with them getting sent to jail......... hell I'd personally have no disagreement with it on ethical grounds if burning the flag was made punishable by death.
Although, the law is not and should not be based on knee jerk reactions and snap judgments, as that's how the slippery slope of eroding constitutional freedoms begins. So, criminalizing any form of "symbolic speech" seems like a potential start to a slippery slope, and it's probably a good thing that legislators stay as far from the edge as possible. As a citizen, I feel that legislators must not criminalize anything that appears to be protected speech or looks like it might be symbolic speech, even if I am utterly enraged by it, like I am with flag burners.
However, as someone who believes strongly in God and the afterlife, I believe that the judgment day will come for flag burners. While they may not be punished here on Earth, make no mistake, they will be punished. In hell. No, I do not know this for a fact, and no I have no evidence of God or the existence of any afterlife other than faith. However, my faith tells me that people who burn the flag are going to find themselves being burned as well......... in hell. No, I do not know this. I haven't had a near death experience where I saw the divine, I'm not a medium, I'm not someone who would have any reason to know what happens after we die. I don't even go to church very often, other than perhaps holidays and other special occasions. All that I'm saying is that it's in my gut and my general inkling is that those who commit evil in the world, and burning the flag in "protest" is evil in my mind, will suffer consequences for their actions after death. But due to the "slippery slope" nature of legislative behavior, it's much too dangerous to attempt to punish them here on Earth.
On a side note, no I am not referring to proper disposal of a tattered flag that involves folding the flag properly, placing the folded flag on the fire, saluting the flag, keeping one's attention on it........ and remembering those who died to protect our freedom, saying the pledge of allegiance, and then not directing one's attention elsewhere until the fire is put out. If someone attempts to follow the proper procedure because they didn't follow the procedure accurately due to misinformation, no I don't think they're going to hell for it or feel that they are reprehensible people, obviously. I feel that blatantly burning the flag as a sign of disrespect, stepping on it, or intentionally disregarding it in any way is reprehensible. And no I am not referring to a flag that accidentally touched the ground while it was being folded, as long as one was taking steps to avoid it, it's not desecration in my opinion unless it was INTENTIONAL. The people who desecreate the flag INTENTIONALLY are pieces of shit, and even if they broke no laws, I believe that they will go to hell....... and justice will be served. But it won't be in a courtroom, it will be by God.