PCT veterans look back. Those that had a great hike see changes. Many think that if it's different than when we hiked it's not going to be as much fun.
Of course, when we hiked there were probably ten times as many people as "way back when." Those people were probably saying the same things the year we hiked.
I much prefer hiking by myself in general, but I really enjoyed the Kick-off and Hiker Heaven and PCT Days. If everyone is hiking the same direction, and most are, fifty people a day will not result in mobs of people seen at all times. Want to avoid people? Start early. Start late. Hike SOBO. Avoid the Kick-off and the popular trail angels and bypass popular campsites. I must have left the Kick-off within a few hours of a hundred thru-hikers and had a great time and camped alone in a beautiful spot the very next evening. And the next.
If you think the trail is ruined, that's probably what you'll find. If you think all the same awesome scenery is still there, you're right. If you think you can hike solo 99% of the time if you like, you're right. If you think your fellow hikers are one of the best parts of the experience, you're right. If you think the experience is what you make of it, you know the secret of happiness.