When A Show Betrays

This is about How I Met Your Mother, spoilers ensue:

Last night's episode seems to confirm a theory that I was not familiar with--that the Mother in the title is dead in the near future--sometime between when they have their kids and before Ted starts telling his teenage kids how he met their mother.

Yes, this makes sense for all kinds of reasons, as enumerated at Slate, but as Alan Sepinwall argued last night, this seem to be a pretty crappy way to end a show that has been aimed at this love story.  That the love story is a tragic one?  Oy, that sucks given that this show deferred and delayed for so long.  They actually ended up casting a great Mother, Cristin Milioti, and it would have been great to see more of her this season. 

So, that was a big fail, but to kill her off?  Hmmm, I guess they might still pull a switch on this, since the show has been chock full of stuff over the years.  This may not be as big of a disappointment as the last season of Lost but that is because Lost was so very good in the prior seasons.  HIMYM had lost its fastball a while ago.  Still, we are watching to see how it finally comes together.  But killing her not that long from now?  Before the kids reach their mid-teens?  Seems like an awful to pay off Ted's years and years of heartbreak.  He gets left at the altar, his best friend marries the women who loved too much (yeah, as in bury that plot thread a few seasons ago rather than resurrecting again and again), and so on.  So heartbreak + heartbreak + short term joy + mega-heartbreak= yuck.

So, I feel a bit betrayed.  Anyone else?