How I Met Your Mother was envisioned as a comedy when it first picked up, but at this point it is clear the writers want the show to be a soapy drama. That's the only excuse because this certainly was not a funny episode. They have Thomas Lennon playing an odd character, they have fart jokes, the humor is just not there.
And I don't care about the mother at this point. Maybe if they told us SOMETHING we'd still be interested, but these teases don't build anticipation,t hey take away from it.