To add on to this, when MV was first released, it did not have a Dark Theme. For those of us who dislike bright things, or have our eyes be hurt by overly bright things, it is a useful, if not needed addition to the core program. In addition, there were things that the core program as itself either could not do or was vulnerable to. If I recall correctly, there was a memory leak that caused issues that absolutely needed to be fixed for the program to remain functional.
As an addition, due to the most recent update, you can create child characters for projects. For some, this is essential, as it can add a much needed element to the game. For myself, particularly, my most recent project has a little kid as a protagonist. Had the update not occurred, I would have had to commission someone to make child sprites for me, or worse, attempt to resize a regular spritesheet, which would have been ugly. Also, you can't create plugins for the engine itself, nor can you change anything about the base program. You can create external character generators, as some people have, but you can't write a plugin to fix the program if a bug appears. That, particularly, is the main difference between plugins and updates. Plugins, in this instance, only effect the game being made by the program, while the updates influence the program itself.
I understand your frustration with not being able to properly update MV, whether by lack of space or simply not understanding how to, (As per your prior topic regarding out-of-date plugins), but updating software is absolutely essential for its continued growth. Security issues or bugs, glitches, and other errors can pop up that need to be addressed. I've had my own share of trouble dealing with updates, believe me, but the additions that were added, like the resource manager for instance, heavily outweighs the impracticality that is not updating.
I hope you're able to get everything to where you need it to be, and if I seem particularly harsh or rude, I apologize in advance. I'm simply addressing the root of the issue so it can be solved.