You asked...I think you have to keep an open mind and use ALL the comments to continually be improving your product. Instead of getting defensive, look at this board as an opportunity to receive legitimate, honest feedback. If you have any experience at all (and it sounds like you do) you should expect that not everybody is going to love everything. Just my $0.02.
And for the record, no, I don't think you were trying to promote your site for free (the most common form of spam in these parts)...although you might want to keep the flame-retardant suit handy if you don't respond to honest feedback (read: criticism) well.