There is a problem with attitude that whatever *I* want or what is comfortable for *me* is okay. There is a lack of respect that plays in our life when we try to justify what we see as fine...that can lead to all kinds of things that may not be biblical,but there is such a thing as unappropriate.
I have seen it before...it is a lack of respect,a casualness before God that is obvious to others. I was in a church once where the men who were passing the offering plate were wearing tennies and jeans,not because that is all they had,but to make a point.
I have also read about a pastor that wore sandals to preach in to make people feel more comfortable coming to church...red flag....that is the seeker sensitive mentality that church should become like the world to win the world,a lack of trust in God's word.
I think it all boils down to this...we can dress comfortably,modestly,and appropriately when coming to church,which I think should be your very best...not more expensive,but a certain style that shows respect and honor...I personally do not feel that wearing long shorts is *unbiblical*,but I do think a degree of casualness shows disrespect to a Holy God.
God is more concerned with our heart for from it flows the wellsprings of life...but what we show outwardly reveals a lot about our heart...dressing appropriately should be a part of all christian's walk. We should all examine the why and how of what we wear. are we doing everything for the glory of God? Are we seeking Him above all else? Do we want our lives to reflect Him or us and our wants?