Rather than sense of wonder, the primary virtue of mainstream science fiction has been exclusion, or a continued winnowing of topics and media from the writer's toolkit.
1935 - Weird Tales readers revolt against the inclusion of Dr. Satan, an anti-hero with mystical and scientific powers in the vein of the Shadow and Doc Savage. Excluded from science fiction are the hero pulps.
1937 - John Campbell takes over as editor of Astounding Science Fiction, ushering in the era that would bear his name. In the drive to root science fiction in plausibility, planetary romance and space opera are excluded from mainstream science fiction.
Early 1950 - The Futurians attempt their revolt in the desire to move science fiction readership and fandom to the Left. Their stories championed science fiction as a vehicle to examine social issues, typically at the society level instead of the personal. Excluded from their science fiction are engineering and heroism.
1960s - The New Wave movement attempted to raise literary quality through the use of soft science fiction. During this time, a section of the movement attempted to rename the genre to speculative fiction. Rather that attempting to reunite science fiction, fantasy, and horror into a weird tales genre, these writers instead excluded science itself from science fiction.
1970s - This decade might be called the Crazy Years of publishing. Through a perfect storm of market forces and legal rulings, the short fiction market, where mainstream science fiction was birthed and once thrived, was replaced by books as the vehicle for science fiction's great conversation. From now on, short fiction is effectively excluded from the mainstream of science fiction thought.
2000s - Patrick Nielsen Hayden, an editor at TOR, claims that there are too many libertarians in science fiction and seeks to correct this through promoting Left-leaning authors. Unless you are lucky enough to write for Baen, conservative values and ideas are excluded from science fiction.
2004 - Mundane Science Fiction publishes a manifesto that seeks to remove all speculative technologies from the stories, reducing them to Howells's idea of "stories about the plight of the 'common man,' just living an ordinary existence" but keeping times, technologies, and settings to an immediate near-future. Mundanes removed any flight of fancy or speculation or even future from science fiction.
2014 - Social Justice Advocates beat the diversity drum, promoting the buying of stories from women, American racial minorities, and the minorities of sexuality. In doing so, they insist that stories must also include said minorities and that readers should stop reading books for white men. If, by accident of birth, you are white, straight, or male, you are excluded from science fiction.
What techniques and topics are left to build a sense of wonder with?