Aside from the quirky interpreations of "eg" and "ie" that triggered this decision, the abbreviations "e.g." and "i.e." are actually problematic, especially when dealing with non-native speakers (or even simply people who had no exposure to Latin).
"e.g." means "exempli gratia" -- I am fairly confident the majority of readers in an international audience (or maybe even a national one) will not actually know this and come up with their own personal backronym (like "ergo" or "example given").
"i.e." means "id est" (literally "that is") -- I know for a fact that even people with some exposure to Latin get this one wrong and instead think it means something like "in exemplum", which actually leads to people using it incorrectly when they should actually use "e.g.". I know this is what I did as a teenager in Germany (while learning Latin in school) and I know that this is what many of my German colleagues tend to do, simply because it seems like an obvious equivalent of the German "zum Beispiel" ("for example").
In the context of a website that explicitly tries to use simple English when possible, I think it is perfectly valid to preempt this confusion and not use phrases which are not actually English and can trivially be substituted with unabbreviated English equivalents in prose (whereas even the unabbreviated Latin would likely not help the reader).
EDIT: I'm not saying you shouldn't use "e.g." or "i.e." ever. I personally use them all the time. But it's absolutely consistent to avoid them when you're trying to use simple language to be understood by a broad audience with varying levels of comprehension.