Ten years is a long time to get to Shodan. I took that long, but I did not train seriously for many years. Also, devoted a lot of time to developing our kids program and starting my own family.
I am told that in a traditional Japanese dojo (assuming you train a lot, maybe 3 or more times per week) the journey to 4th Dan (Yondan) is about 10 years. A lot of factors can influence this, including the level of your instructor and the level of people you have available to train with.

When I started with my instructor, we were all white belts and he was a Nidan just starting to teach. It's 14 years now and none of us (except my Sensei, who passed away) are Yondan, though all of his original students who stuck with it are now black belts and teaching. Newer students in our dojo progress faster, possibly cause they have plenty of black belts to train with.

Anyway, I would not be too confident critiquing the art if I haven't reached Yondan myself. If I think I see something missing in Aikido, how can I assume the weakness is Aikido and not my imperfect mastery of it?

I am curious, why is it important to you to answer the verbal attacks of sport fighters?