I think you need to first define what you mean by Art. Let's look at what Oxford Dictionary says:
"Art: noun. The expression or application of human creative skill and imagination, typically in a visual form such as painting or sculpture, producing works to be appreciated primarily for their beauty or emotional power."
So, in essence, art is represented in three category: creativity, skill, and imagination. If I am not misunderstanding, you are saying that today, skills aren't needed (this is not entirely true, but we'll revisit that later), but an artist still needs creativity and imagination. To me, a painting or any artwork is an expression of the creator's thoughts and beliefs and his / her perception of live, reality, and social message. It does not have to be limited to a painting. It can be a painting, music, clothing, furniture, a handbag, or movie, a novel or just about anything that requires creativity and imagination.
So you mentioned that you cannot grant a piece of work created by Photoshop the same status as an oil painting. I believe that's subjective, again, based on your personal belief of what constitutes as "art". However, as defined above, anything that requires creativity and imagination can be categorized as art. At least for me, I know I am unable to create anything beautiful in Photoshop or on Canvas because I lack such creativity.
Lastly, you are saying using photoshop can turn you from a "novice to master". That is not true. Photoshop is not magic -- it does have tools to make things easier, but you need to know those tools very well. However as aforementioned, the most important is one needs to know what message you want to send with your painting. Without the the ability to understand and appreciate what's "beautiful" I don't think a novice can become Picasso overnight even he is a master of Photoshop. Similarly, I can feed a sequence of mathematical equations and create music, but without knowing what's pleasant, I cannot become Mozart overnight either.