Rochelle Walensky singles out "the men who have sex with men community". That quote is literally her words.
There are many men, often because of cultural pressure (mostly in the black community) who don't identify as gay. (Herschel Walker's son for example). When a health department official would address something towards the gay community, many at risk men would say Well I'm not gay, so that doesn't apply to me. It was found that addressing it as "men who have sex with men" was more likely to get their attention.
And yes, monkeypox became the problem it is today via gay circuit parties (once a year events in various cities where all the good looking gays with disposable income fly from around the world to dance, do dance club drugs, and have sex). We can even trace the path of monkeypox. Someone visiting from Africa (where it is more common) went to Madrid and spread it via sex to a few people. One or more of them then went a weekend or two later to a big gay circuit party in Antwerp. Some of them went the following weekend to the big gay circuit party in Maspalomas. Then everyone flew back home and spread it throughout the world. Clusters have been found after the big gay circuit party in Chicago (memorial day weekend). Also in New York, Los Angeles, Miami, Dallas, etc.
Yes it can easily spread via sex. But it can be spread via casual contact too, similar to chickenpox. Fortunately we already have a vaccine that prevents it, the smallpox vaccine, which was given to all children at birth and then at age 10 or so in the US until 1974. (A little bit later in Europe, well into the 80s in Latin America, and into 2000 in China.) Got a vaccination scare on your shoulder? That's from the (live virus) smallpox vaccine. (Today's vaccines are not live virus and do not cause a scare.)
I got my second smallpox vaccine in 1970 or so, at school! The entire class was marched down to the nurses office and each of us were injected.
People who got the smallpox vaccine as a child, even 50 years ago, are about 80% protected from monkeypox. It is recommended that people like me get one booster now, while those who have never had the smallpox vaccine get two shots a month apart.
This is a big deal because if it starts spreading from child to child like with chickenpox, then every child will need the smallpox vaccine again.
There is plenty of vaccine available to inoculate the target community to quickly get this under control, but there have been logistics problems that need to be worked out quickly.