I could think of some reasons why the stroke order is important.
In modern times, especially in the digital times, there should be a standard of the stroke order, so that when people input characters with "stroke order" method, it's useful to program the input method consistently.
We have some general rules of the stroke order, such as "from up to down, from left to right". I think this is reasonable, because you will feel comfortable when writing that way.
Remember, you are not a machine or computer, you can't precisely control the positions of each stroke, so you can't write the strokes here and there to get a beautiful character.
Also, I want to say that there are really official standards of stroke orders. In mainland, it's 《现代汉语通用字笔顺规范》,and in Taiwan, it's 《常用国字标准字体笔顺》.However, I know 《现代汉语通用字笔顺规范》is a recommended, not a mandatory standard.
When I was a student, my teacher taught me the correct order for some characeters, but not all characters. I just reviewed the standard, and found I had some mistakes in the order against the standard.E.g. the standard says that “heart" radical(left part of 情) is written: /，、，|， but my order is:|, /, 、.
I think minor "mistakes" are acceptable, because the stroke order is not something like math, you can't set up a definite system to specify everything. I think that's why the standard is not mandatory.