Eh, I don't think it is. Most members of Congress aren't minting money trading stock. The revolving door is far more insidious. Pointing at this lets pass make minor reforms, chuck a surprise at the eternally cynical and keep the goose that lays the golden eggs.
The partisanship of the accusations also helps galvanize support. Republicans can claim to be sticking it to Pelosi. Democrats can better cover their flank. The base will eat it up. Nobody in finance cares. And like two members of Congress will be slightly diminished millionaires. Broadly, a win-win. (Even if more marginally than presented.)