Posting party affiliation doesn't really help spot the bullshitters. There are bullshitter Republicans AND bullshitter Democrats.
However, the poster who was complaining about posting party affiliation was complaining about how Slashdot tends to only use the party label when a Democrat does "good things*" or a Republican does "bad things*." Democrats doing "bad things" and Republicans doing "good things" don't get a party label.
When a serious organization does this over time, this leads to the perception that "Democrats are the party that do "good things"" and "Republicans are the party that do "bad things."" Which, of course, is itself bullshit.
Slashdot is NOT a serious organization. I think they label Democrat "good things" and Republican "bad things" but leave party labels off the reverse because that will antagonize posters, who will then post a bunch of arguments back and forth. EXACTLY like this thread. All this means is more ad dollars for Dice.
If Slashdot wanted to be taken seriously, they would put a party label on every politician on first reference. Sadly, they don't.
*By good things and bad things, I mean "popularity among the Slashdot groupthink." On technology vs. business issues (like this bill) most of Slashdot will come down pretty clearly on one side, even if the bill is popular among the population as a whole. Obviously, on issues like "Is it OK for politicians to sell Russian weapons to terrorists," Slashdot groupthink is pretty in line with the population as a whole.