What money? If it grew on trees…well, okay, we already covered that. Well, if it grew on properly maintained trees that did not silently kill the neighbor's goat, it would simply get eaten by the same goat, which really is lucky to be alive. Arboriculture may seem to be lucrative because it is so expensive for those paying for arboricultural services. However, most of the expense is for overhead, from expensive machinery to seriously expensive insurance.
The workers—most groundsman start out making about $30k. However, only the biggest and least humane of tree services provide other benefits. Climbers generally earn a bit more—up to $50k annually, but again, without benefits. (Not having insurance in this gig is a bad non-benefit, as you can imagine.) Consulting arborists and insoectors actually do not make much more than $60k, even after spending decades in the industry. Very few earn more than $100k...but there are outliers.
The only professionals in arboriculture who actually earn good money are those who own or have interest in tree service businesses. The business is risky, however, since competition with less tree-loving services is fierce. It's cheaper to do arbor work when you really don't care about the trees or flora around them. The industry is so under-appreciated and under-respected that clients almost always do business with the cheapest bidder. Clients just want to see short-term results. So they cut corners wherever they can and green light "hack jobs."
Hack jobs subsequently necessitate even more expensive repair work or removal of damaged trees. Getting the work done properly the first time may be a bit more expensive in the beginning, but is almost always less expensive in the long term. Since trees live about a century, and many live many centuries, the long term really is…well, long. Trees which are worth maintaining are worth treating properly. No one wants to remove a tree that was worked on just a few years earlier, particularly since trees are the most substantial residents of the landscape.
The sad truth that should be shared as tactfully (as barbaric arborists can manage) with potential clients is that most work that urban trees need is caused by the abuses of those who were paid to maintain them earlier, or gardeners who maintain the landscapes below. Hack jobs cause major structural problems. Gardeners almost always dump so much water onto lawns and the rest of the landscape that even riparian trees (that naturally live near water) can not survive. They drown and rot, or simply fall over because their roots are so shallow.
Help! I can't swim!
Even if this tactful explanation gains the confidence of a potential client who becomes a real client, rates need to stay competitive. Very few arborists earn the sort of notoriety that allows them to charge whatever they want to for their work. Only "froufrou" landscape designers get to do that. Unless the industry is restored to what it was when horticulture and arboriculture were still respected, it will remain impoverished. Alms for the palms?