They added the word Pro to the model to differentiate it from the old Macbook models they used to sell and marketing came up with the idea. The laptop was not optimized, or configured with professionals in mind per se. Its useful to professionals but they didn't set out to fulfill professionals needs but rather consumers. If they did, then the GPU, memory ports would be different because professionals need more ports, more memory etc.
I had a whole long post written and I lost it thanks to the time-out of this site
So short version:
YES and NO
When the Intel-era started, Apple Inc had just 1 line in idea (13", 15" and 17") to replace the iBooks and PowerBooks.
A bold move, but combined with stepping to Intel CPUs and the idea that a 13" would be unmarketable for (high-end) consumers, they broke their idea up into 13" MB and 15",17" MBP.
Unfortunally, the extra costs of producing a plastic casing proved not to be a good idea business wise, so Apple Inc gave in the next refresh the MB and MBP the same alu-casing. The sale statistics showed them that the world was ready for a 13" high-end notebook, so they rebranded the alu 13" MB to MBP.
Not to alienate their MB buyers, Apple Inc again reintroduced their plastic casing, which again wasn't considered cost effective and now with having a 13" MB and a 13" MBP in their lines, they found out that the MB cannabilizes the MBP line, but not the lines of the competition.
Add the introduction of the MBA line and the mess was complete, so their idea was to kill off the MB, which they did (every refresh of the MBP and MBA made the gap bigger, but it took them still 3 years, which is long in the world of notebooks).
Now the MB is only used in the educational system, just to get students to be aquinted with Macbooks and to facilitate their transistion to MBPs and MBAs once they enter professional life and start earning real money.
Yet this will not be enough to justify the development and production of the MB line, so expect this program to stop in one or two years, when the gap with the new MBPs and MBAs becomes too big.
It's just a textbook case of a company that didn't proceed with their initial idea because some factors came together (or didn't) at the wrong moment.
- investing in new technology (Intel)
- breaking with tradition (replacing iBooks and Powerbooks with one line)
- miscalculation of the market (a 13" as high-end consumer product)
- the (low-end/normal) consumer products weren't available yet (no MBAs at the switch, but they were in the R&D pipeline)
Would it have been wise of Apple Inc to take the chance and just brought out the Macbook in 13", 15" and 17"? We will never know, probably not, but if they would have succeeded the only thing that would have been changed on the long term would have been the name: the high-end line would have been called "Macbook" instead of "Macbook Pro".
Nowadays they are getting there also, doing it in several steps, but the high-end is called "Macbook Pro" instead of "Macbook" because of that.