It is your choice
But there certainly are good blogs on thumblogger and you miss these. The only thing is that the definition of good a bad blogs is undefined.
A blog with only pictures can be a good blog for example babelogs.
A blog with a picture and 1 sentence can be a good blog in a network of blogs that don't depend on search engines (which is a wise thing to be not to depended of search engines).
A blog feeded from multiple rss feeds can be good if you feed it with traffic from other sources like link list or freesites. One can say good blogs are blogs with a lot text, but that is only true when you target certain targets.
But of course what your site wants is a lot of text, cause a aggregator copies text from someone else blog post and copies it on their own site.
In addition the thumblogger rss feeds are shrinked down because of aggregators like your site borrowing blog post (without permission of the orginal blog owner?).