The analogy doesn't work. Tefillin is an obligation each day. Matza is, in theory, only an obligation at the seder. The rest of the week matza is an option, but hametz is an absolute prohibition.

I still think this so-called minhag is strange, but that's a different issue.

even if not an obligation it is still a mitzva the rest of the week as well. how can you have a minhag not to do a mitzva? can I have a minhag not to move to eretz yisrael? can I have a minhag not to wear tzitzis?

in our shiur we recently had a discussion about, and then asked a rav for clarification, about since chazal gave the option of selling chametz to a goy perhaps one should not burn more than a symbolic amount of chametz, as it might be called bal tashchis, as chazal gave a different way that is not wasteful.
The conclusion, and the rav cnfirmed this, is that chazal gave a way out of it for those who want, but the torah still has a mitzva to burn chametz (biur, however you want to define it). you cannot get around the fact that the torah still calls it a mitzva, even if you have another way to do it.

eating matza on pesach is a mitzva. regardless of whether it is a chiyuv or not. how can you have a minhag to not do a mitzva?

I've heard of this minhag before, to only eat the required shiurim of Matza at Seder, and no other mataza during the week (not sure about Lechem Mishna on Shabbat and Chag).

I don't think that there is a Mitzva to eat Matza during pessach, except for the Matza Mitzva on Seder (which may only be a "Drabanan" if there is no Korban Pessach)

Matza is a chiuv deoraita on fisrt night in our time as well, it is not dependent on the korban (contrary to the maror). The Gra specifically says that eating matza on the rest of Pessach is indeed a mitzva deoraita, even if not a chiuv. It exactly the same thing as mitzvat sukka: only on the first night do you have an obligation to eat in it, but every time you live in the sukka during the chag you fulfill a mitzva.

I bet your also going to have a problem with people who don't learn Torah the entire year because they might come to learn Torah on Tish B'Av.

Much better chumrah than the one I heard about a Rav who learned Torah on Tish B'Av because he was curious of what kind of Gehenim he would get for it.

Actually, this minhag is not too surprising. What is the minhag of many during Shmitta? NOT to eat the produce of Israel, and only eat imported food. I can't believe that G-d would rather have us eat imported food during Shmitta than eating produce of the Land of Israel. Seems sorta backwards to me.

It's a disease and it's called OCD.

This Minhag seems like a shtus, but if you think about it, it actually makes more sense than the Minhag not to eat Kitniyos. The reason is that this (no-Matza) Minhag is based on a chashash, though far-fetched, that there may be real Chametz in the Matza, while Kitniyos, by definition, can never become Chametz.

Actually, there's a mitzva to wear tefilin all day, every day. We don't do that for fear of not having guf naki, so we make do with the minimum. Same thing.

its amazing to me that so many people that are ignorant are willing to put in their two cents. after the seder the gemara refers to matza as reshus and although the gaon and a number of rishonim assume there is still some mitzva involved, many rishonim argue. see also the netziv in his haggada where he writes that if one has kavana to get a mitzva after the first night he transgreeses bal tosif. the comparison to tefillin etc. is absurd. even the bais halevi only ate a kezayis each day and only because of the position of the gaon etc. after that he wuold not eat more. etc etc.

I know there are different opinions regarding whether it is a mitzva or not to eat matza after the first night.
either way the Torah says For 7 days you shall eat matza, and some people (very few to be fair) are saying no we wont.

Now, I dont really care what he does, and I am not telling him what to do. I dont tell anybody what to do. He, you and anybody else, can do whatever makes you happy.

I question whether this can be called a minhag. To me it still sounds backwards to say you have a minhag to do something that is opposite of what the Torah says. Regardless of whether it is a mitzva or a reshus. Perhaps it should only be called a hanhaga.