There have been lots of suggestions for how to improve linux / unix for a very long time.
The first great war I remember, and I'm sure there were more before I was around, was DJB vs everyone. For the most part, I think his designs, "weird" as they were / are, are still better than almost every crackpot variation of them that's come since.
DJB is a genius, responsible for all of the non-NSA asymmetric cryptosystems, symmetric cryptosystems, and authenticated encryption algorithms supported by TLS (curve25519, chacha20, Poly1305). He's also the one who got us off of the footgun-by-design, broken-random-number-generator-will-spray-your-privatekey-everywhere nondeterministic nonce signature schemes prior to Ed25519 (the first standardized signature scheme which required deterministic nonces). Oh yeah and the only post-quantum cryptosystem that OpenSSH was comfortable shipping.
And pottering gave us pulseaudio. The gift that keeps on giving.
What I said was that the first holy war of unix I remember is the DJB vs everyone else.
As far as I can tell, as odd as DJB's designs may have seemed, they were and are ... way better than what was and still hold up today; most of the following "lets unix better" designs seem to just adopt some of DJB's designs, typically poorly.
Systemd certainly seems to have cribbed elements of daemontools et al, but seemingly none of the notion of "least privilege" ...
The great thing about unix is that there are no "wars" over these things, because everybody gets to decide for themselves.
Well at least that's how it was before systemd -- and all of DJB's unix work long predates systemd. By the time systemd came around DJB had been focusing on ECC exclusively for almost a decade.
The way I remember it is that most people didn't understand DJB and just kinda ignored his work, while a bunch of other people recognized what he was on to and integrated his ideas into software with frendlier user interfaces. For example, runit, which is PID1 for Void Linux to this day, and s6, which is PID1 for both Liminix ("NixOS-on-your-wifi-AP") and Spectrum ("Qubes for Nix"). Indeed increasing numbers of NixOS users are ditching systemd for s6.
Anyways I don't remember anything close to a "holy war".
The first great war I remember, and I'm sure there were more before I was around, was DJB vs everyone. For the most part, I think his designs, "weird" as they were / are, are still better than almost every crackpot variation of them that's come since.