Uh, Lycan was picked more than either, Shadowfiend was picked more than either, Morphling more than both combined, Nature's Prophet was picked more than both combined, Engima was picked more than both combined, and all of the aforementioned heroes had a higher winrate than either one. I feel like there's something to what you're saying with regards to the last sentence quoted (mainly because I don't fully understand what "deathball" is supposed to be, I've just heard it referenced with regards to Necrolyte), but I don't think there's a lack of farming heroes or carries. If you didn't see the matches then I can understand why you would think that. Then again, maybe I'm not fully understanding your point (which is why I engaged in the first place).
Lycan, SF, NP, and Enigma are not hard carries. Like I said, Morphling is the only hard carry being picked frequently who also wins games. Most likely because he's unkillable AND he has early game impact with Waveform AND he can split push.
abija's explanation of the deathball is correct but it makes it sound like there's strategy involved (i.e., picking a timing). My point was that a lot of games are devolving to deathballs not because it's a good strategy but because it's too dangerous and unrewarding to have people going around alone unless they're dedicated split pushers. It would be nice to see two parties of 2-3 heroes achieving things at the same time on different parts of the map but that seems to happen less and less.