As one of the freshly minted PPLs from a few years ago I can add some perspective to what is already an interesting debate, having just taken my first flight today in two and a half years.
What put me off two years ago was primarily the cost together with the weather combined with a lack of confidence which only comes with more hours which is expensive - catch 22. The other issue is the aircraft and at the risk of offending some people on here, a C-172 doesn't cut it for me as it looks like something out of the 1960s and to be frank doesn't look that safe. I know that last statement is irrational but that is how many people will look at it...
I've been bimbling round this week enjoying the fantastic weather so I booked to go up with an instructor today - result, I can still fly albeit a bit rusty but after 2.5 years I can still land an aircraft and I loved every minute of it until the invoice hit me at the end. Over £200.00 for less than two hours! At least the aircraft is modern, being a Katana which helps on one front but it is still a costly business.
Until modern aircraft are available en masse at reasonable rates then there will always be this wash out and although you cannot do anything about the weather, once rates are reasonable and hours can be accumulated then the confidence will increase and so on and so forth.