Random Thought of the Moment:
ever notice in conversation you can't emphasize i unless you put it into bigger font? i.e. if you wanted to emphasize tech in this is tech you're talking about, you would just write, this is TECH you're talking about. but if you just write a capitalized i, the message of an emphasized i will not be conveyed. such as, well I did better, or well i did better, don't look very different in terms of emphasis. notice that the same effect doesn't occur when emphasizing a, because a is significantly different from A.