It's an MMO. You can't play the whole thing alone. There will continue to be new content that requires teams. This is normal. There will probably also be new content that is soloable.
Who says you can't? It's an MMO by the fact that it: Contains an player set economy, places to socialize/chat, endless story progression, and the ability to group. Pretty sure its not set in stone that it MUST contain group only content.
The fact is that a: You must complete Infected to do The Cure, and I'm sure the next missions that come out require The Cure to be competed as well. b: It's only going to get worse as time moves on, less and less players will want to help new ppl through the old content, and I highly doubt there will be enough "new" ppl around to do it with, they come in trickles, not masses. Am I asking for a solo version right now? No, they can wait a few months, but if they wait to long new players are going to be in a crappy position trying to get groups together for "old content".
It's not exactly that ppl don't like to team up, its that they can't because of time, waiting for 20mins to find a group and 10 mins for ppl to get there, and maybe an hour to get through, the whole group is screwed if ppl have to leave.
Join a fleet.
Give them your availability times.
Work out a time plenty of you are available.
Set a time and place to meet and do the mission together.
You say you do not have much time well joining a fleet lets you arrange things so you make the most of the time you have.
Your all obviously missing the point, right now its fine, yes, but a month or so down the line everyone will be tired of the "old content" and not bother to help NEW players with "old content" while they're busy farming new content. And seeing as how it is you MUST finish them In order just to move on it is going to be even more of a pain in the rear for NEW players.
Look at WoW, nobody ever does lvl 60\70 raids anymore and here you have this fresh to the game lvl 60\70 who will probably never set foot inside because ppl are off doing the new stuff, true you CAN skip those raids in WoW as they are not chained in the way STO is, yet WoW is even more of a tragedy because here you have this hard worked on beautiful content that just collects dust for the rest of its day, because it can be skipped, yet takes up 8gbs of my hard drive space...