Perhaps the easiest solution to all this would be to simply introduce novvortismoj (neologisms) like "matro" as a female equivalent of "patro", "soro" for "frato" etc. You could even import the terms from Ido, which to its credit has a "non-sexist" way of handling it. This would be much less cumbersome than appending "-iĉ" everywhere, does not contradict the Fundamento definitions of "patro", "frato" etc., and you could still use -iĉ occasionally for other words when you find it necessary to stress masculinity. In fact I would have very few objections to this setup, aside from the slight (+20 extra vocabulary words) additional learning burden imposed on the learner.

I agree with fenris_kcf that language shouldn't be considered absolutely static. I feel at times almost like we must dogmatically follow Eurocentric-style usage (some people, for example, are not comfortable when I use SOV or OSV word order, or that I say "feliĉu" instead of "estu feliĉa". Well, it's just easier for me to express myself that way, my native language is not so restrictive!)

Interesting question though: what if the default were "female" and "-iĉ" were used only to expressly indicate masculinity? Would that be equally a problem? I don't think I would feel particularly offended by it, even though it would take a bit of getting adjusted to.

Kirilo81:For me gepatro is not immediately understandable (a shemale? hm, unlikely, so probably a father or mother.

To me the meaning is very obvious because it's just the singular form of "gepatroj", which is well understood to mean parents. There's no need to analyze the word according to it's constituent morphemes and I think most speakers would not do so when encountering it.

Tempodivalse:
Interesting question though: what if the default were "female" and "-iĉ" were used only to expressly indicate masculinity? Would that be equally a problem? I don't think I would feel particularly offended by it, even though it would take a bit of getting adjusted to.

At least one English example of this occurs to me:

widow, widower

"Iĉism" isn't kontraŭfundamenta, but as with "riism", "ŝliism", "naism", and so on, it will just seem unnecessary to your typical Esperantist.

NONE of this stuff is new. The 'naistoj' have been quiet for a couple of years. I expect we'll be talking about that one again at some point. Then we'll switch over to "ŝli" as the only solution to the eternal li/ŝi issue. Or "ri", I think that does the same thing if I remember correctly. We can then spend some time hassling out what we all hate about the accusative and why it ought to be dropped, and by this time we'll be ready to work on the whole patro/patrino sexism problem once again. Although that whole "na" thing might be worth looking into around then, too.

In the meantime...