To be fair, the localisation times are to blame for this gap year being more "brutal".
2015 was the first year since 1997 where there was no main series game released in the three major territories.
1996: Red/Green (Japan), Blue (Japan)
1997: Nothing
1998: Yellow (Japan), Red/Blue (US)
1999: Blue (Retail - Japan), Gold/Silver (Japan), Yellow (US), Red/Blue (EU)
2000: Crystal (Japan), Gold/Silver (US), Yellow (EU)
2001: Crystal (US), Gold/Silver (EU), Crystal (EU)
2002: Ruby & Sapphire (Japan)
2003: Ruby & Sapphire (US, EU)
2004: FireRed & LeafGreen (Japan, US, EU), Emerald (Japan)
2005: Emerald (US, EU)
2006: Diamond & Pearl (Japan)
2007: Diamond & Pearl (US, EU)
2008: Platinum (Japan)
2009: HeartGold & SoulSilver (Japan), Platinum (US, EU)
2010: Black & White (Japan), HeartGold & SoulSilver (US, EU)
2011: Black & White (US, EU)
2012: Black 2 & White 2 (Japan, US, EU)
2013: X & Y (Japan, US, EU)
2014: Omega Ruby & Alpha Sapphire (Japan, US, EU)
2015: Nothing
As such, even though the games had been out in Japan for ~6 months, the west had just got them so they were busy there.
This was all due to localisations gradually shrinking down to be nothing. If they were still ~4-6 months, we'd have had 2013 as our gap year in the west, and had XY in 2014 and ORAS in 2015 and this "long gruelling" gap between reveals wouldn't have felt anywhere near as bad.
Still though. We've had longer between release and reveal before
DP launch -> Platinum reveal = 20 months
BW launch -> B2W2 reveal = 17 months
We're currently approaching 14 months since ORAS. Plenty of time.