Excessive spam of smilies really can transform a professional comment into a degraded piece of junk. It just makes it look obnoxious and childish. If it's to poke fun at something, I would only say a maximum of 2-5 smilies per (long) paragraph. Maybe less than that.
Sure, I know.
I know 2 guys here who posts smileys like that.
Edit: that doesn't include me.