Open source software developers probably won't want to touch this with a bargepole. Oddball copyleft licenses are a pain in the ass to deal with an invariably incompatible with every other copyleft license including the GPL.
Came here to say much the same. GPL / non-MIT generally = avoid, because IANAL and don't want to figure out if I'm in the right or wrong.
Note that EUPL is explicitly compatible with GPL and a few other licenses in that it allows you to license a derivative work under GPL (or the other license) instead of EUPL.