Not a big deal to me, if mostly in the "and this is how I can filter out assholes" way.

If someone I watch puts up ads, one of a number of things is true:
I block the ads. No problem.
I decide they have a different purpose to their journal than I do to reading it. Unfriend.
I decide that their content is worth reading even with the ads, just as I do for webcomics and other ad or semi-ad supported media.