If you're a very smart dev at one of the biggest tech companies in the world, getting paid a quarter of a million dollars per year working on a niche team that handles a small section of a single product, you will probably get bored pretty quickly and start focusing on the how. It's a shame really; some of the greatest minds of our generation are being put into rooms to work on animations for buttons on virtual DVD cases and Photo Books.
The silver lining is all these tools are given away for free. The tools so great and their corporate creators so cool that you can just have them! A cynical reading is that they are only given away because the competition can derive no value from them... In fact, forcing your competitors to retrain every 6 months when you release another major version that breaks all existing projects will only slow them down and fill your coffers! The new whatsapp will never get off the ground, because the devs were too busy rewriting babel files and the money ran out... you just saved a cool $18bn.
If these frameworks were really the key to anyone's successful business you would not know that they exist.