If what we wear says something about who we are then what would you say the clothes on a homeless person says? My wife was very poor growing up and was treated badly for how she dressed. Is that who we are?
No, but you are making a false dichotomy based on an appeal to emotion.
I concede the possibility that there are people who may be considered by others to be dressed poorly but who are actually doing the best they can with what they've got. The pastor ought to know his flock well enough to know who these people are and stand up for them if necessary.
But in this thread we're not talking about specific people, we are discussing general policies. And generally, people should dress their best for church, and those who serve at the altar, due to the nature of their duties and their higher visibility, should take this more seriously and offer a good example, by mandate if not voluntarily. Altar service is not a right, it is a privilege to serve where angels fear to tread, it is a privilege to minister in roles proper to minor clergy, whether absent or not. It is not a burdensome imposition to insist that servers comport themselves with as much respect as they can, interiorly (prayer, fasting, sacramental life, etc.) but also externally (dress, hygiene, decorum, etc.).
If the pastor has, among his altar servers, one or more who can't meet "basic" dress code requirements because of economic hardship, he has every right to excuse them from those requirements or hold them to what they can do. But what happens when you lower the standards for dress in the name of "someone who can't afford it" is that everyone else gets lazy, even if they have no excuse. That is a disservice not only to themselves and to God, but also to "the poor" they are supposedly defending.
As Schultz wrote earlier, this is a very recent problem. Moreover, it doesn't even affect all Christians. African-American Christians are well known for continuing to dress in their "Sunday best", and they are hardly "the 1%". In my experience in the US, ethnic Indians, Armenians, Arab Antiochians, most Copts and Syrians, Russians, and Greeks dress well for church and for altar service. Ethiopians and Eritreans even have a specific form of white dress which they always wear to church, so it doesn't matter if you're rich or poor--everyone wears similar garments. In my experience, it's the "American" Orthodox, EO or OO, of whatever jurisdiction, converts and/or "N generation" born in the Church, who seem to quibble over these things in order to justify doing whatever they want. I see it in my own community, where my own peers were raised to dress in shirt and tie for church and now their children are wearing shorts, tee shirts, sneakers, etc., and they themselves are showing up sloppier than their parents would've permitted, even though total household incomes in those families are easily in the lower six figures. Let's not throw "the poor" under the bus in order to defend our right to act like spoiled brats in God's house. God can find a way to respect honest spoiled brats, but he hates liars.