As the second sort of builder, who also knows the previous system very well, this new system is not a step backwards. It's actually a step forward. Even though stabilizers give a restriction, it's eliminated other restrictions and allowed for less blocks to make a function ship. Chambers gives us options for more RP purpose of a ship.As you know, there are at least three competing kinds of builder.
The first sort of builder builds because they need a ship to fly around in to do other things. This might not be the most skilled builder in the world, and to this person the requirement for stabilizers is "stupid and adds nothing to gameplay" because it's just one more hoop they have to jump through to get a working ship that they can use for other things, and it adds nothing to their gameplay because they are more interested in doing other things besides building. This kind of player is most interested in innovations that reduce the amount of time they spend doing things that are more like chores rather than fun. For this player, the new reactions are a step in the right direction but the system still isn't quite where they'd like to see it.
The second sort of builder is an RP builder. They will spend hours and hours making interiors and exteriors, and carefully consider that the appearance of their ship is exactly how they want it. For this player, the requirement for stabilizers is "stupid and adds nothing to gameplay" because it's a mechanical consideration that constrains the appearance of their ship a lot more than the previous system did. If they want their ship to actually be useful in game play, it's a serious consideration and it can prevent them from building the ship they want to build. This kind of player is most interested in innovations that reduce the number of limitations they have regarding ship design, and the new reactor systems are a step BACKWARDS for this player.
The third sort of builder is the optimizer. You see a lot of PVP players lean towards this end of the spectrum. Their interest is in making the most mechanically efficient ship they can given the constraints of the game, and they typically only care a little bit if it's ugly (a so-called "doom cube"). For this player, the requirement for stabilizers is "stupid and adds nothing to gameplay" because they are interested in having the most skill-dependent mechanical systems possible so that they can master those systems and get an advantage over their opponents. As counter-intuitive as it is, this player benefits most from having obscenely complicated mechanics that add "depth" and keep the player interested in discovering new and better loopholes, bugs and exploits. This player's goals are directly at odds with the casual builder because to them, the casual builder is prey, and the bigger the divide between skilled and unskilled, the more it benefits the PVP'er. This kind of player is most interested in innovations that add complexity to game play, and the new reactor systems are a step backwards because they simplify power generation.
For the optimizer, the new systems gives a lot of options through chambers for depth.
The issue here is the point of stabilizers, its just an arbitrary block that has a single purpose to balance another block without actually doing anything.