Dude, you are far left kneejerk progressive. Studying politics is NOT going to give you gravitas except with other progressives simply because everything you see is colored by your preferences. Take the role of Speaker. True, her role is to pass legislation. The role of EVERY Representative is to pass legislation. It's kind of what they do. That does not mean that her other roles - represent her party and keep them in power (by making sure she and they do not alienate the voters), schedule votes, moderate debate, work with the minority, keep the important stuff ahead of the politically desirable but unimportant stuff, set the rules, represent the House ceremonially, be prepared to step in and serve as President (second in succession) - are not equally valid functions and thus equally valid measures of success. I could argue that passing legislation is a smaller part of the Speaker's role than of an ordinary Representative with a few committee assignments, who has little else to do but see that her preferred legislation passes. Just because passing (progressive) legislation is her most important role TO YOU does not mean everyone will see it so. For instance, there are roughly sixty soon to be unemployed Democrats who probably very much wish Pelosi had passed less legislation - and that's just in D.C.
By almost anyone's measure, a Speaker who passes some legislation but in doing so costs her party a historic loss is NOT successful. A successful Speaker moves forward an agenda that makes the country happy, not just an agenda that makes her happy, because at the end of the day the Speaker must represent America, not merely her own constituents, in a way that other Representatives do not.