The make up of the C of E is biased in various ways - race, age and class. I say this as someone who attends regularly. We are, for the most part, a white, older, middle class institution and we need to work to change that. I think there is tacit class bias (I'm not saying overt prejudice but rather unconscious bias) going on here. I think you are judging people on what they wear because clothes are bound up in our culture with a whole bunch of signifiers of class and many who don't attend church regularly but do attend for special occasions are more likely to come from a working class background.
If we as a church are ever going to be genuinely welcoming we have to stop caring about this crap. Church is come as you are. Wear what you want, bring your problems, bring your strengths, be yourself. You are welcome, just as you are.
That's all very nice and noble of you @stripydeckchair, but to come to an event like a Christening or wedding in the clothes you would do your gardening in, is a pisstake, and very disrespectful.
Also speak for yourself about the Church being white, middle-class, and old people. The Church in my village is a mixture of middle class 20-something and 30-something couples, (some with kids some not,) working class single mothers, (and couples with kids,) a few very elderly people, some middle aged folk, and half a dozen Asian and black families. We don't need to 'work on' anything.
People don't attend Church because they can't be arsed, and many claim they are atheist, but, like I said, they like to use the Church for their convenience when they get married, for the 'pretty surroundings,' and also to get their kids christened. They never attend again, EVER, after the wedding or Christening.
The Church is good enough to use for their convenience, but not to attend any other time apparently.