[rant]
It's not a complete deal breaker for me, but it certainly is frustrating and silly IMO. Some of my favorite mods, CDSEO, Altered Cart's OPC, are encrypted and require ioncube. I think those two are worth the trouble, maybe.
The thing is it makes upgrading, testing, and moving your site difficult. Depending on how the module is coded, moving the site to a test IP address may be impossible or at least difficult. Xcart mods UK are the worst with this. They literally code their mods in a way that completely breaks your site if there are license troubles.
IMO it is pretty pathetic to encrypt the source of your little mod with your few lines of code, when QT gives away the full source of X-cart. The beauty of this cart is it's open source, we can and will make it into whatever we want it to be. Now I understand a dev wanting to "protect" their work and keep thieves from simply copying the code and using it on multiple sites. But the vast majority of merchants that I work with it is all they can do to operate one site.
I can't tell you how many times I have struggled with some licensed encrypted mod, attempting to disable it so I can just load the site up on a local test server to perform some modification. X-cart does it right, display a warning message, but don't disable the site! The other issue is that the only person able to fix or work on the module when it breaks, you guessed it the original module creator. Simply because they want to hide their little code. Skilled developers that could recreate their code or adapt it, are also the ones that appreciate the time savings of modules more than anyone. I charge my clients $50.00 an hour. CDSEO is around $200.00. There is no way I could even begin to write that module in less than 4 hours.
I think my biggest gripe with Ioncube and Zend, is that the right distros have to be installed for your server config. What works on your server today, is probably not going to work when you upgrade, move or expand your hosting capabilities.
Great men and women all over the world have come together to bring us all powerful open source tools like Apache, PHP, MySQL and the like completely for free. But these guys won't show you their scripts even though you paid for it? It just rubs me the wrong way. I have never bought or installed a module that I didn't want to tweak in some way.[/rant]