The way LR and PS are made to work together is, you use Lightroom to move, apply presets and develop a photograph. For 85 % of amateurs, it's all they will ever need and you can avoid the five year learning curve and absurd expense of PS. But let's say you want to go a step further and remove a power line from a photo, or do pixel by pixel editing, then you go one more step in Lightroom and PS opens with your photo in it.... When done, you can drop back into Lightroom. Photoshop was designed as a stand alone program, with no file handling, so bridge was created to move files around first. Lightroom was built from the ground up as a photography tool, it is tremendously powerful and can do most photo stuff... Until you get way out there. Lots of pre-Lightroom people are out there, so there is a disproportionate number of PS users than there would have been if Lightroom and PS had been available at the beginning of digital photography. For them, well, they know the tool and are comfortable with it's archaic interface and steep learning curve... You can tell I'm a real fan of PS after using it for several years, actually the suite... With Illustrator. I had deadlines, and would be kept up late at night trying to fine some simple command that was hidden until you pressed the "ubscure key" number 34. JD
I'm not new to PCs I've used a huge percentage of the software packages since available since 1985... PS doesn't stand for PhotoShop, it stands for Photoshop Sx... Hmmm, I feel better... I didn't realize how much hostility I hold for that program. If your a rich masochist , I highly recommend it.