They're struggling to earn a living because the 'classic motorcycling community' (that's us) doesn't value their services highly enough for them to earn a decent living, let alone enough to take on an assistant and train them up to run the business.
We get what we pay for... or in this case, we no longer get what we're not prepared to pay for.
So many people seem hell bent on getting the cheapest answer to their classic bike problems, regardless of the quality of what they end up with or the impact of their actions on the rest of the trade.
All those fake NGK Sparkplugs, cheapo innertubes that rip apart, bargain pattern parts on eBay... Sadly there's a market out there for this stuff and I'm glad I'm not trying to make a living selling my services to people who run classic British bikes (people with Italian and German classics seem happier / resigned to paying more) on a budget more suited to the 1950s.