I don't think it's intentional though, because there is no consistently and the animation doesn't really make sense. Also, if that's how it suppose to work, the player health should be shown on the screen while operating the installation, and the installation health won't be as important.

It is intentional because it allows for you to skillfully steal a turret away from it's operator.

With the case of the turrets of the previous build, if someone sneaked around and took out the turret operator of either the Blaster or Missile Turret he could then proceed to hack that turret and use it against the team that was supposed to be both protecting it and protecting themselves with it. But with the glitched Railgun Turret, the only way to stop the rampaging gunner of one was to destroy the turret. This nuisance caused many players who did not intend to man them to outright destroy all of the Railgun Turrets at the beginning of the match instead of risk the enemy team getting ahold of them.

And I'm not sure what you mean by "there is no consistently" (read: consistency) when I already explained that there is no set position on the turret --- no SINGLE seat, as it were --- to operate the turret from. All sides of the turret have a monitor and control panel. That is the point that your character controls it from. The animation shows the character putting his hands forward as if he is reaching out to touch the control panel. Admittedly, now if the character is far enough away from the panel when he accesses the turret he probably appears to be reaching out into the air, but I haven't yet taken notice having only played for a short while yesterday.

Finally, the health of the installation is very important. If it is about to blow up you should know, so that you can decide whether you need to bail or if it's safe enough to stay until its shields become restored.