It's the grand tradition of a workman owning their tools. As long as a carpenter has a hammer and saw they can find work. I propose finding your nearest plumber, carpenter, or welder and telling them about a new plan where they pay a monthly fee that would be enough to buy their tools outright in three years, but they have to keep paying and if they can't pay you come take the tools away.
To play Devil's Advocate, a lot of automotive repair and industrial companies *do* lease their tools. SnapOn uses this business model, to great success I might add.
In fact, a lot of mechanics in training that go to a Technical College for automotive repair are required to rent their own tool chest from SnapOn, which costs several hundred dollars a month, on top of tuition. Though, it's actually more of a "rent to own" or financing scenario; basically SnapOn says the tools cost X to buy outright, but we'll rent them to you for Y per month, once you've paid X+25% you can keep them, in the mean time, if you stop paying we get the tools back. (Typically these tool sets can cost between $5000-$10000 this way!)
Some auto repair, industrial and manufacturing companies will lease tool sets from SnapOn. It tends to be very expensive, but you *do* get a high quality of service. For example, if one of your tools breaks, you lose a socket or you need some specialty tool for a day that's not part of your set, you call the local office and the SnapOn man shows up in his box truck full of tools with a replacement or whatever you need.
For a small to medium company that needs hundreds of thousands of dollars worth of tools (plus maintenance costs), leasing for $2000 a month (or more, or less) may actually be a smart move (in fact it may be the only way they can operate in the beginning).
Having said that, allow me to return to the side of the angels: I've seen at least one business close down (and several others on the verge of bankruptcy) specifically because they leased their tools. Essentially, business was slow for a couple of months, cash got very tight, their tools were taken away, then a big order came in and they couldn't fulfill it.
I would *never* lease, rent, whatever *any* tool that my business depends on to operate. For me, that's EDA software.
SaS makes sense for something like web based invoicing software, because I can always do by hand with spreadsheet software if I have to and I can keep PDF copies of all the invoices I generate (plus a CSV file of everything); it doesn't make sense for PCB software, especially if I might need to open that file 10 years from now, but can't because AutoDesk decided to shutter Eagle completely.
Basically, if I can't archive a VM containing Windows, my PCB software *and* the design files for *each* client project, which allows me to go back and make changes tomorrow or ten years from now, then it's no good to me. I know a lot of other designers that feel the same way, so good luck with your monthly approach to Eagle. Call me when you decide to go back to a perpetual license. (I'd be OK with an optional yearly update fee on top of that, so long as I have the option to own it.)
Edit: You know, I don't think this would have received nearly as much backlash if Eagle was in the same league as Altium or Cadence... But they're not!