In my last post, I got a comment about the lettering on a page I worked on. The question was, what makes lower case comic book lettering 'yucky'. I should point out that I am not a professional letterer, but I have bounced around the business a few years and I know what I like. As for why the lower case style sucks, lets take a look at a before and after. I took a page from an issue of SHIELD that I inked years ago and re-did the lettering.
My lettering is a bit clumsy, but the smaller lower case letters are harder to see. Plus the lower case style kills the drama from art.
I don't know why MARVEL changed lettering styles in the first place. You used to find the lower case in self-published or independent comics, but not the larger companies. It was for a short time and I am glad that fad is over.