Have you ever heard someone say that comfort was a bad thing? My guess would be that it is not likely. We all generally think of comfort as a good thing. There are numerous references to it in Scripture that tell us that we worship "the God of all comfort" and that we are to seek to "comfort others with the comfort that God has given us". Yet pretty much all of these ideas of comfort have to do with giving comfort to someone who is experiencing something painful and not with the common idea of being "comfortable".
Being "comforted" is not the same thing as being "comfortable". The first refers to receiving help and assistance after or during a time of great suffering; the second refers primarily to personal physical feelings. Our modern understanding of "comfort" is related more to the idea of being relaxed or at ease. It relates to being without restrictions, or inconveniences of any kind. This is quite different from the biblical concept of being given the grace of being free from fear and finding a peace in Christ. This is not to say that is wrong to be relaxed or to be without inconveniences, but despite similar words, these are two different things. If we do not keep this distinction clear, we may fall into a dangerous attitude. This is the attitude that "comfort" is more important to us than it is supposed to be; when this happens "being comfortable" can become an idol. Whatever we give more authority than the Lord is, itself, an idol.
When we make decisions based on a desire for comfort, that can become a serious problem. Our first thought when participating in any liturgical action should not be "how physically comfortable can I make myself while doing this?" It should be, however, "how can I honor the Lord God?" This is especially important because there may be things that are "comfortable" that actually dishonor God. As an example, would it be honoring to God for us to sit back on a couch with our feet up on a coffee table during the consecration at the Mass? It would be comfortable, yes, but not honorable. It would, in fact, show disrespect and a lack of reverence for the Lord. That is a time for kneeling, not lounging.
Let us take a comparative situation: imagine making your decisions based on food. One might say that since the Church requires a minimum of one hour fast before receiving communion, then it would be better not to go to Mass because that would mean having to give up food for a time. Or, one might say that the type of the wine used in communion is not his favorite so he refuses to receive the precious blood. Similarly, we could imagine someone saying that meat is not all that bad for you, so it is OK to ignore the Lenten abstinence from meat on Fridays. For each of these we would say that the person was being rebellious based on his own personal likes and dislikes; the wrong grounds for determining one's actions.
The distinction made above between being "comforted" and being "comfortable" is important here. Many treat the idea of "dressing up" for Church to be a grave hardship or terrible suffering. "I'm not comfortable when I wear something like that." It is not an issue of suffering for someone to dress nicely when he attends Church; it is an issue of personal dislike. "This is who I am, take it or leave it" is not an attitude of holy submission. Yes, we are supposed to "accept people for who they are" (apart from sin), but people should want to honor God by presenting themselves respectably. The point of the Mass is not to make us feel good inside, it is to glorify God and receive the grace of Christ. Does Christ want us to be "comforted" when we come to the Mass? Yes, but as I said above, that is not the same as being "comfortable". Being comforted refers to something that we experience in our very souls; it endures and does not change with various outward circumstances. Being comfortable refers to physical ease.
Furthermore, respectable attire does not need to be "uncomfortable" per se. That is a common misrepresentation. Yes, there are some fancy clothes that are quite uncomfortable (to be honest, the alb, cincture, maniple, stole and chasuble the priest wears for Mass are often very uncomfortable). The "comfort" that seems to be so necessary to many today is related to what the Scriptures refer to as "luxury" (e.g. Sirach 37:29, James 5:5). This is related to the attitude that says "I have to be comfortable and have nice things", and not "I want to honor God and am willing to experience discomfort for it." We are, after all, called to suffer for Christ; are we really willing to say that we cannot be uncomfortable for Him?
How do you make your decisions about how you dress in the presence of Royalty? Is there an effort to show respect for the King of Kings, as well as for the others present? If we are called to love God with our "heart, soul, mind and body" then we must also recognize that what we do with our body will influence what is in our hearts and minds. It is difficult to have deep reverence when everything about our person says "casual". Let us each consider how to give to God our best, both in body and in soul.