I actually like what they did with the "1 ship" approach, it is honestly what I would have done if I were in their position. If I might indulge a bit I will explain what I think their reasoning was.
Roughly speaking, in X3 (Reunion, TC, and AP), there were 3 general classes of ships; fighters, corvettes, and capitals. The problem was that even though these types of ships should serve incredibly different roles, due to either design or tech limitations, even the smallest fighter and the largest capital were basically the same. The only thing that really changed were models and stats (or stats on the equipment). What they did in rebirth was really separate these out as unique entities much better suited for their specific purpose.
Capitals are no longer pilot-able because now they are true capitals, huge lumbering behemoths that are very customizable and bristling with surface elements. The problem with capitals from X3 is that they were too much like normal ships due to the constraints placed upon them to keep them at least semi-usable as a player ship. By removing this Egosoft was able to take capitals in a new and much more distinct direction, one that is much, much better and fills a previously unoccupied place in the universe (something between a station and a player ship).
Fighters were changed for essentially the same reason only on the other end of the spectrum. They became drones which are small, unmanned, specialized, and semi-disposable. That is kind of how fighters are in X3 which is why players don't usually tool around in them for the whole game. BUT, piloting fighters is actually quite fun, so player's retain the ability to personally control one via VR, which has the added bonus of providing far more tactical flexibility. Player's are now able to "spend" fighters (they personally fly) to accomplish goals instead of the binary choice of a loading screen.
Ultimately they kept the "Corvette" type in the realm of player ship. This makes sense as players usually selected a corvette as their player ship anyway as they are a nice balance of speed, power, and defense. Somewhat unfortunately you only get one for X:R but it comes with a lot more options. I always ended up flying the same ship for most of the game anyway so I'd much rather have an awesome customizable ship.
I actually really hated flying most ships. People talk about how awesome being able to fly every ship was but honestly out of hundreds of ships you really only flew a handful anyway, usually whatever was "best" at a particular attribute. For example, there are many scout ships, but most people just used a Kestrel because it was the fastest. For me keeping track of and maintaining my handful of "player" ships (the main one and then the handful I used to perform specific tasks) was a giant pain and I am glad to see it go.
Hopefully, in the future, I wouldn't mind a small selection of really awesome, really customizable player ships instead of JUST one, but in this case more isn't better; better is better.
