It seems important to note, however, that doing good work on LW is superior to not doing good work at all.

Edit:

In conclusion, if you want to do important work, cross-post it if you must, but don't do it for LW exclusively. Big fish in a small pond always looks kinda sad.

Most places that would be cross-posted with LW would be even smaller ponds. So I'm not sure this supports your point here.