>> My real questions are based on beauty vs. popularity <<
I think those are the wrong questions.
The questions should be do you want a unique experience and are you up to the challenge?
The WCT is truly a beautiful trail but as Family Guy has said the WCT can also be a test of your own mental and physical ability. The sign at the trail head office listing the number of people that have been "evacuated to date", pretty much says it all. I can't think of another trail that has such a high number of injuries considering the restricted number of hikers doing the trail. (I had to bail on my WCT trip last year because of a knee injury... I walked out, so I wasn't one of their statistics board and it's the first time a trail has ever beaten me).
As a light weight backpacker you shouldn't have any problem physically but the root balls, rain, wind, fog, ladders, and slippery surfaces (everything is slippery) can take it's toll on you if you are not mentally and physically prepared. Many people leave the WCT very proud that they have completed the trail but during the hike they were miserable.
The reason you should try the WCT is because of the unique experience it provides. I'm very familiar with coastal hiking/camping but the WCT is truly a unique hiking experience. It should be on every backpackers bucket list.
The WCT is a truly international trail, so the people you meet will be a highlight of your trip. The terrain is incredible, with beautiful beach walks, west coast rain forest and unusual trail features (the ladders have to be seen to be appreciated). Beer, burgers, crab and salmon are also a highlight of this trail (just ask anybody that's hiked the trail!).
If you go before June 15th you do not have to reserve a spot, just show up and go. There will be half the number of hikers on the trail at this time of year compared to prime time. Most people don't drive to/from the northern terminus, take the West Coast Trail Bus or a boat and save your car... again, both of these add to the adventure.