It took Into Darkness four whole years to be released after '09 (four and a half if you count it's original release date of December 08), and Beyond was only released nine months ago. Regardless of how early 14 was announced, Quinto's quote doesn't change the fact that it's still too early to hear anything concrete either way and/or be writing it off completely.
That too is part of the problem IMO. You need to strike when the iron is hot. Too many years pass for every other installment. As others have expressed more eloquently, there was great excitement for Trek after Star Trek '09. Now, 8 years and two sequels later that seems to have evaporated. And it looks we will be waiting even longer for Star Trek (1)4. How many Star Wars or even Guardians of the Galaxy films will be released in that time?