Victorian-era translations of Jules Verne are very mixed.
Some translators just didn't bother to get the science right (this is evident in "20,000 Leagues Under the Sea" and "Journey to the Center of the Earth.") They would mis-translate units of measurement (using feet instead of meters) and just simply eliminate the "boring geology" that they didn't understand.
Verne was also a Frenchman and the English translators were mostly British. So any anti-British or liberal tendencies were removed so as not to offend Victorian sensibilities. This sometimes included racist stereotypes that Verne never intended.
Finally, Verne was (and is) not seen as a serious author by English readers (eg: your own comment dismisses Verne as merely "entertaining literature.") His works were frequently abridged and marketed as juvenile fiction. After a while, nobody bothered to translate his works because, the copyrights of the original translations were in the public domain, and they were "good enough."
This is slowly being corrected by some fine new translations (the 20,000 Leagues translation mentioned elsewhere is important in that regard.)
This was actually a very big problem with Russian Literature. Constance Garnett was a prolific translator of Tolstoy, Dostoyevsky, and Chekov. Apparently her speed of translating the massive works made her popular with publishers of the day.
Today her works are still being published, despite their clear inferiority to newer translations that are not yet in the public domain.
There really is a quality difference. Several of Jules Verne's works were serialized in news papers at the time and then a slap-dash translation was made very quickly so they could publish them in other countries. The translations were often so bad that Verne himself commented on them. In some cases the translations omitted and abridged parts of the works as well.
It very much does a disservice to Verne's reputation to read such poor quality translations. Indeed, perhaps the reason why you do not consider Verne's work to be "great poetry" is because you've never been exposed to any good translations.
I only really began to appreciate what work it takes to make a definitive translation when I read about all the effort that Walter James Miller and Frederick Paul Walter put in to Verne's 20,000 Leagues Under the Sea -- it's no mean feat.
I also spy some cool short works of Phillip K. Dick (Second Variety), some Cory Doctorow, some Harry Harrison. Very nifty!