The right beans, prepared correctly, and "in moderation," are probably a lot healthier than most of the things the "typical Amerian" is eating these days.  However, my argument is that if you can eat a tasty and satisfying diet that is also healthy, why bother with things that are not?  I also used to eat a lot of beans.  They did upset my stomach and they were not very satisfying.  Of course, taste is subjective, at least to some degree.  In any case, you can do some internet searches and see for yourself.  Here are a couple of things I found on quick searches:

Titre du document / Document title Nutritional significance of lectins and enzyme inhibitors from legumes Auteur(s) / Author(s) LAJOLO Franco M. (1) ; GENOVESE Maria Inés (1) ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s) (1) Departamento de Alimentos e Nutrição Expérimental, Universidade de São Paulo, Avenida Prof. Lineu Prestes 580, CEP 05508-900, São Paulo, BRESIL American Chemical Society, ETATS-UNIS Résumé / Abstract Legumes have natural components, such as lectins, amylase, and trypsin inhibitors, that may adversely affect their nutritional properties. Much information has already been obtained on their antinutritional significance and how to inactivate them by proper processing. Chronic ingestion of residual levels is unlikely to pose risks to human health. On the other hand, the ability of these molecules to inhibit some enzymes such as trypsin, chymotrypsin, disaccharidases, and α-amylases, to selectively bind to glycoconjugates, and to enter the circulatory system may be a useful tool in nutrition and pharmacology. Trypsin inhibitors have also been studied as cancer risk reducing factors. These components seem to act as plant defense substances. However, increased contents may represent an impairment of the nutritional quality of legumes because these glycoproteins and the sulfur-rich protease inhibitors have been shown to be poorly digested and to participate in chemical reactions during processing reducing protein digestibility, a still unsolved question.

SOURCE:  http://cat.inist.fr/?aModele=afficheN&cpsidt=14353437

And:

"Lectin may contribute to the atherogenicity of peanut oil."

Lipids. 1998 Aug;33(8):821-3.

Read the abstract of this study at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9727614&dopt=Abstract language=JavaScript1.2> </SCRIPT> language=JavaScript1.2> </SCRIPT>