To fit within the context of the Star Trek universe, though, they HAD to treat singularities like physical, detectable elements. Throughout Star Trek: The Next Generation subspace irregularities and various singularities are not only detectable but also visible, and to avoid upsetting the core fanbase that approach had to be held consistent.

Also, from what I understand, the approach to time travel isn't exactly time travel in the linear sense, but instead in the multi-verse sense, so that nothing Spock Prime experienced has been undone or still failed to happen, but in this new, alternate variation of the universe all that comes after Kirk takes command simply has not yet happened, and may not happen at all. An entire episode of Star Trek: The Next Generation dealt with this subject, in which Worf was the only one noticing he was hopping realities.