Most people do not 'hack' their scope, they don't have the skills to do that. A few smart guys are doing that and the rest are just copying the process.
Agreed, most of the folks running the keygen against their Rigol gear (myself included) are being the EE equivalent of script-kiddies, not that there's anything fundamentally wrong with that in this context.
If you're talking about hacking serial numbers or/and unlocking features on your scope, that's plain stealing
With all due respect, I think you're mistaken, again at least in terms of Rigol. Their decision not to close any of their licensing security holes, either with firmware updates or new designs for new equipment, fairly clearly illustrate the reality that 'hacking' their equipment is a marketing/segmentation exercise for them. They've done what so many companies long to do, they've worked out how to charge different prices for the same product, dependent on the individual customer's willingness (and possibly ability) to pay. If Rigol _didn't_ offer the ultra-hackable DS1000Z and DS2K series scopes, I'd be furiously trying to decide between all the low-cost scope options in the marketplace. But since they do, the decision becomes easy, I'll buy theirs and feel like I'm getting a ton more for my money. I wasn't going to spend more than $500 for the scope anyway, the question is solely one of which company gets my money. And it costs Rigol _nothing_ for me to hack, assuming that I wasn't going to pay for the feature in the first place. And I wasn't; as a hobbyist, if I need to decode I2C and I don't have a scope that'll do it, I'm going to spend $30 on a USB dongle to do the job, not $120 on a license for my scope. But they do get the sale, and more important than a piddly little sale, they get me using their products, getting used to their interfaces, making happy memories showing my kids what music looks like as a waveform, all on my Rigol Brand Digital Storage Oscilloscope™
And that could be priceless (or at least worth a lot more than a $400 scope).
Same with the DP832 I'm also about to buy. Feels like a bargain, even if it's not really. It absolutely does feel like it to me. Bloody genius.
If anyone is interested in the topic, this is an _excellent_ Joel on Software article, well worth the read if you have any interest in marketing;
http://www.joelonsoftware.com/articles/CamelsandRubberDuckies.html