There are some starting at the very beginning of this thread. Did you even care to read it before you decided to comment?
There is also this entire thread: http://geekhack.org/index.php?topic=43309.0
Now whether or not you agree to those reasons does not take away from the fact that they are valid. And if you're going to try to say that they all amount to "I want it", then what does any argument against this change amount to beside "I don't want it"?
Now that's just not summing it up fairly.
The arguments for
are simply that
some people want bigger avatars - there are no technical or layout reasons. What you think are valid arguments are reasons why some people
want them bigger - to show more detail, be more prominent, etc.
Reasons such as 'because it would fit', and 'Steam does it', are not valid arguments, not reasons to make a change at all.
Some of the arguments against are technical/layout related, such as not expanding the margin to intrude on posts. There are also arguments based on focusing on post content, which are certainly valid. And of course some others are reasons why people "don't want it" - no need for more detail, don't want them more prominent.
So in a fairly unbiased summary (I tried, at least) that's 3 groups of reasons against versus 1 group for.