I don't think people understand what the role of the Speaker of the House is, tbh. Her job is to make sure legislation gets passed, legislation that is supported or needed by the constituency. In order to legislate effectively you need to at least attempt bipartisanship, otherwise you get gridlock.
Nowhere has she said "I'm willing to undermine everything about the party platform and what my constituents want in the pursuit of bipartisanship".
Also Democrats aren't a monolith, not every Rep is going to be 100% on board with every piece of legislation. Getting individual Reps to support legislation is also her job.