I've seen many occurrences of live shows where musicians used headless guitars. This kind of guitar is not very common, but it seems particularly chosen by reggae musicians.
Is there a trend between reggae musiciens to use these guitars?
When it comes to bass guitar, yes - the Steinberger headless bass has had something of a particular association with reggae.
Flabba Holt and Robbie Shakespeare are users, as is asian dub foundation's Dr Das and Lyndon "Ace" Webb of Black Uhuru.
From a personal point of view I'd say they are pretty common at reggae shows.
One brand that springs to mind is the Steinberger. Their XT and XS series were very popular in the 80’s and 90’s for reggae and dancehall and are still very popular. To me they’re the third best reggae bass.
In fact you would be hard pressed to go to a reggae or dancehall show back in the day without seeing one. They’re very light, which makes for comfortable use when doing long shows and they also produce a deep and one of the best reggae bass sound (strange for their small size).
Of course reggae pre-dates this particular instrument and many other basses are used for reggae, live and for recording. But there's certainly something of an association.
No it's not a genre specific trend. In fact personally I associate a headless guitars more with metal than anything else.
They are starting to get more popular with all guitarist in general. One reason could be because headless guitars noticeable reduce the weight of a guitar which when playing out often every pound of your equipment counts. The also seem to have better market now a there are companies like this devoted to selling them.