Yeah, but you are then building for the sake of building. The crew limitations are a pain, so is getting the resources for the ships. If you are a purely combat player, having to mine asteroids for 95% of the time to get a bigger ship, or to get a necessary reactor isn't fun gameplay. Then you build three large-ish ships and you cannot crew them all at the same time because people don't want to work for you. Especially when you are a completionist and want to "finish" a system before heading out, you quickly stop getting fame and either need to jump to a higher difficulty system (which your ship won't survive unless you know the "meta" well), or resort to more mining instead of the fun stuff.

Edit: all of these are choices made by the devs. In combat, you can take over a ship that has an airlock after you destroy the bridge. You cannot then scrap it for valuable parts, since scrapping captured ships nets you no materials back. It is viable for the very first or second sector you go to, when you don't have factories (and finding a ship graveyard and scrapping for metal feels worthwhile) but you quickly outgrow it.