In order to make well-designed software, it's important to know how and why people do things with it. That's all I'm trying to do here: establish why this is really a problem, understand the situation so it can be best addressed, and then come up with the best way to solve it.
One of the reasons I'm somewhat surprised by this particular point about X buttons in tabs is there are lots of places in the UI where different clickable options are close to each other: context menus, properties, toolbar buttons, lists of actions, and so on. Aren't those a problem too?
Perhaps it's just that it's annoying to recover from an accidental click due to the issue with moving tabs. Solving that might mean that there isn't actually such a need to remove the X button. This type of thing is why I'm trying to understand the problem better, rather than just jumping to conclusions and adding workarounds (which as Diego alluded to tend to compound over time, cause bugs, and end in poorly designed software). This is our approach to every aspect of Construct - if someone insists on a change without explanation, it's unlikely we'll act on it, especially as we are always very busy with a huge pile of other things we know really are important. This is also why we have our feature request and bug report systems: they're intended to help make all of this clear so we can actually act on what you want.