English may be easy for e.g. German speakers but English is not simple. Its rules are complex.
English grammar is not simple. It has what (12?) tenses. (on the contrary Russian has basically 3 tenses) And it's full of exceptions. Why 'I see', but I'm looking at you. There's simply no reason. It's an exception. Thousands of them.
> ...and the phonology converges on what is pronouncable by all speakers of the new language (and therefore is reduced in complexity as well.
Let's just take 2 sounds. Th as in this: "This sound, and its unvoiced counterpart, are rare phonemes. The great majority of European and Asian languages, such as German, French, Persian, Japanese, and Chinese, lack this sound."
Th as in "thing": "Among the more than 60 languages with over 10 million speakers, only English, Standard Arabic, Spanish (Spain only), Burmese, and Greek have [it]"
> Of course Esperanto is a jumble as well, but it's a jumble that is entirely artificial.
Artificial != bad. We have tons of artificial things in our life that are awesome!
> it's developed over dozens of years by a large number of speakers of widely differing skill levels whereas Esperanto was thought up by a small number of highly skilled language experts.
That what happens when you let naturally develop: "In general, English spelling does not reflect* the sound changes in the pronunciation of the language that have occurred since the late fifteenth century."
> I'll agree with you that for native speakers of Indo-European langues (like mine, which isn't English, by the way), Esperanto is easy to learn and use. But my point is it is not easy to learn for people who aren't native speakers of an Indo-European language and that if you're going to make these people learn an Indo-European language anyway, you might as well just make it English.
Esperanto is several times faster to learn than English for anybody (given similar conditions). Linguists say it and I second that based on experience.