Because now you invite more negativity (on top of the original negativity and now yours) as people who didn't like their writing may now want to defend themself because they just didn't like the style and aren't part of some "growing undercurrent" who can't appreciate his brilliance because he's not "well-established nor a known expert".

Maybe they just think the writing is overwrought like when you outgrow John Scalzi's lamewad writing after briefly finding it clever in Old Man's War? (I think that's a decent place to end this because Scalzi is a very successful author.)