I don't think hackability is such a big thing, certainly not in business. I bought a DS1104Z-S last year with several options. Wouldn't dream of buying a lower model and hacking it; it's just bad karma to do those things when you're using the stuff commercially. Besides, the money is peanuts compared to e.g. the 6-digit sums we're spending on COMSOL licenses. Ridiculously expensive those.
I also don't think the hobbyist market is that big. If I had to guess, I'd say the biggest piece of the pie by far for rigol is their domestic market, followed by rest of the world commercial, followed by hobbyists. I don't have any hard data though, it's just a guess.
Btw, am I the only one who feels that their decoding upgrades are really not worth the money, since them being limited to screen area makes them only mildly useful?
The DS1054Z is a fantastic overall deal though. I'm not missing the -S functionality either, since it's so cheap that a separate signal gen is affordable for a hobbyist too. And that one will have an UI that probably isn't as cumbersome to use