Why is the price going down?

Because there is a higher supply in XMR than there is demand driving the price down. Also:

  1. Too much speculation. Anonymity only matters for actual transaction, not for speculation. And BTC market is 70% speculation. Alt is even worse
  2. Lack of confidence/market fatigue. People are willing to wait, but only that far. DB, GUI, even website. Long overdue
  3. "fully mined before reaching actual use". This is the "emission curve debate" - note that BTC could suffer the same fate, for the same reason. It was decided to not change it, though.
  4. if ZKP does deliver, Monero COULD lose its main advantage - although ZKP does not have the extensive academic background that ring sigs have.

Also read smooth's point of view. Finally, Monero has always been considered as expensive. So low price mean more opportunities to buy for people previously concerned with the price (source).