Sea Cow came like 1 month after release, not 9-ish.
Separately, I do not think that TLBM line would be watered down. Most sets are quite good and creative, definitely at least on the level of TLM sets. Three years ago this quality would have been considered outstanding. The problem is that general set quality increased so much in the recent years, that the bar to capture out appreciation has moved even higher. This creates a perception of oversaturation for the run-of-the-mill collector. I see this the reason behind LEGO's increased push for high piece count sets, to capture interest and generate hype, as well designed smaller sets are just too common now. Too bad that they are falling into the same trap, they can't just continue making larger and larger sets.