I was always "interested" in trains while growing up, but not living near a railroad track and having a dad who wasn't overly interested in seeing to it that I was brought trackside other than the side window of the family station wagon on Highway 99 during semi-annual vacations to LA from Sacramento. He did not discourage me, and in fact did not do anything to stifle my interest in model RR'ing. There were also a couple of mid-day trips to the Sacramento WP station to catch the passage of both of the daily Cal Zephyrs. My major problem was generally a lack of "access" until I got my own wheels and spent time at Roseville and Elvas. That was in the late 70s, when things were fairly wide open. Today's newbies are confronted with NO TRESPASSING signs and the fear of a hassle. The once-friendly railroad employees are often suspicious of anybody on the right-of-way. Add to that the cost of gas to get yourself trackside (after the costs of the car in the first place and then insuring yourself). The only thing cheaper (in today's dollars) would be the camera--unless you want to go high-end digital, but then that eliminates the cost of film and developing. I am speaking from the bias of a photographer and not a museum volunteer, which in the case of the latter would eliminate the equipment costs, but not the transportation. With all that said, there is simply more to do these days. My kids now divide their time to include things that probably most of us didn't have at their ages, but might have become rich if we had just thought them up 25 years ago.
Aspect #2 of my "hobby" involvement would relate to the model side of railroading. How I pity the young kids trying to start out in this era. That same part of the "no time" philosophy has turned the manufacturers primarily toward the "ready-to-run", high-end rolling stock and locomotives available today. Over on the Model Railroading board at Trainorders, I noticed today a thread regarding an Athearn 3-pack of covered hoppers for a mere $69.95. That is SICK!!! Thank God I collected when there were several manufacturers offering cars in the couple-of-buck range--even for Athearn and MDC quality. I have "blue boxes" with price tags of $1.98 that I can remember buying. Today, so many lines have merged and are being distributed by mega-movers who can control the market. I have lost interest in magazines anymore also because of the percentage of advertising vs. useful content. I do ALL of my purchasing anymore at swap meets.
The younger people entering the "hobby" today have a wall enclosing it that must be overcome first. Even railroad employment has no "family connection" anymore.