Maybe a word from a foreigner here would be appreciated!
Honestly, if I wanted to make
aircraft plural, I would have said
aircrafts. The reason is that unless I come across a situation where I actually have to use the word and someone tells me adding
s is wrong, I have no way to find out!
I remember learning about
sheep when I was learning English.
yen when I was in Japan.
software from MS word that kept telling me
softwares is wrong. You know, with
software, even though I know
softwares is wrong, I just can't get myself to use
software. It just doesn't feel right to say
I have written many software!
I think the reason English is subject to more rapid change (towards regularity) (in comparison with other languages) is that we all have to learn English and we all have different mother-tongues. Naturally, I use English the way I use my language unless told otherwise. (You won't believe how many times I literally translated a common phrase in Persian, only to see my friends shocked by how meaningless that phrase sounded)
And besides not knowing, there may be difficulties also. For example, in my language (Persian), you don't have irregular pluralization. So, by default, I tend to add
s to whatever I want to make plural. (Not to mention we don't have genders (not even he/she), nor do we have declination, nor irregular conjugation. Image then one of us learning Polish!)
Now, my language is at least in the same family as English (Indo-European languages). Think of how messed up an Arab or a Vietnamese would be.
Anyway, that was my point of way. And yes, I'm quite certain English will be subject to many many changes, hopefully towards more regularity, simply because of non-native speakers. (Believe me, I've never seen any European NOT saying fishes!)