I'm sure he was referring to me.
I would like to kindly point out that none of those you listed -- Windows, Linux, Mac, or myOS are "architectures." All of these are operating systems. Examples of architectures are ARM, Amtel, PowerPC( *cringes* ), x86, and x86-64 (Both AMD64 and Intel 64).Thus, you already lack the most fundamental concepts needed to build J.A.R.V.I.S
I never claimed those to be either. If you read my second paragraph, you will see a lot of mentions that has to do with architecture.
Oh, yes, sorry, you are probably right.
This is not to discourage you to try to write your own OS, just that the motivation needs to be right. Fact is that no matter how good you are, it will be a lengthy project. If you are going to do this alone (and you also need to learn while doing), it will easily take you more than 10 years to make something that won't even be able to run any (by that time) modern games or applications. It is easy to underestimate a task, thinking it is easier that it really is, and also underestimating your own abilities too. I used to do that in the past too.
So make sure your motivation is right: If you are doing this just because you think it is fun, and/or want to learn, go ahead! If you are doing this because you have some idea that you will be able to make the next big fantastic OS that everyone should use, for your own sake find something else to do that has a lesser scope than this.
Making simple games can be fun.