A base Linux system has relatively few services (just SSH in simple distributions) so to begin targeting Linux the same way you’d have to decide to go after RHEL or something
Not sure why it shuold be REHL, there are linux counterparts for most bundled software you mention so a comparison against a base linux system + e.g. samba/vnc/nginx/... still seems fair. All of those have had (sometimes severe i.e. root escalation) vulnerabilities in the past, but answering the question whether it's 'as frequent' is pretty hard to answer. I would also guess towards 'no' though.
Yeah, there are applications that are very common, but still exploits against them won’t be as universally applicable as Windows ones. You’re likely to find a Linux server with either Samba or nginx or some VNC software but all at once is less common, and there’s a lot of variety with web and VNC servers.
Not sure why it shuold be REHL, there are linux counterparts for most bundled software you mention so a comparison against a base linux system + e.g. samba/vnc/nginx/... still seems fair. All of those have had (sometimes severe i.e. root escalation) vulnerabilities in the past, but answering the question whether it's 'as frequent' is pretty hard to answer. I would also guess towards 'no' though.