I want to know how the Standard Model theory got such "generic" name.
The Standard Model of particle physics got its name from the late Sam Treiman. It was first coined in 1975 when Treiman, together with long time friend Abraham Pais, published a paper in which they used "standard model" to reference the four quarks theory.
The term 'Standard Model' was first coined by Pais and Treiman in (1975), with reference to the electroweak theory with four quarks.
-- Cao, Tian Yu. Conceptual developments of 20th century field theories. Cambridge University Press, 1998.
Sam con-fessed to me, without remorse, that he coined "The Standard Model," a curiously flat name for the marvelous theory of quarks and leptons that he helped to build. I forgave him then, and I forgive him now|but we still need a better name!
-- Quigg, Chris. "The state of the standard model." arXiv preprint hep-ph/0001145 (2000).)
And Treiman's own distinguished students such as Jonathan Rosner:
The "Standard Model" of elementary particle physics encompasses the progress that has been made in the past half-century in understanding the weak, electromagnetic, and strong interactions. The name was apparently bestowed by my doctoral thesis advisor, Sam Treiman, whose dedication to particle physics kindled the light for so many of his students during those times of experimental and theoretical discoveries.
-- Davies, Christine TH, and Steve M. Playfer, eds. Heavy Flavour Physics Theory and Experimental Results in Heavy Quark Physics. CRC Press, 2010.
Professor Treiman was a "major force" during the synthesis of particle physics theories into the Standard Model. As an eminent educator, he strongly influenced the Standard Model's birth both through his own work and through his dozens graduate students, many of whom went on to be great contributors to the Standard Model and particle physics.
The origins of the term are somewhat obscure. In the book "The Rise of the Standard Model: Particle Physics in the 1960's and 1970's," the authors write:
In the late 1970s elementary particle physicists began speaking of the "Standard Model" as basic theory of matter.... The model is referred to as "standard," because it provides a theory of fundamental constituents--an ontological basis for describing the structure and behavior of all forms of matter (gravitation excepted), including atoms, nuclei, strange particles, and so on.
The term "standard model" was faddish in several different scientific contexts in the 1960s and 1970s, however, I think the reason it became adopted permanently in physics was the influence of the use of the term in astronomy. In astronomy the model of the evolution of the universe which today we know as the "Big Bang Theory", was frequently referred to as the "standard model" because there were many different theories of the universe, but the Big Bang theory was by far the most popular, so it became known as the standard model. For example, you can read about this usage in the lecture "Relativistic cosmology" by Ellis, Cargese Lectures in Physics, 1973.
So, that was 1973. Right about this time the same term started to get applied to then-current Weinberg-Salam theory of quantum particle physics. The earliest reference to this in a paper I could find was, "Weak nonleptonic decays of charmed hadrons in models with right-handed currents" by G Branco, RN Mohapatra, T Hagiwara, DP Sidhu. Physical Review D, 1976. In this paper it says,
"A detailed study of the properties of these particles has been done, based on the standard model of weak and electromagnetic interactions in which the four-quark model is incorporated into the Weinberg-Salam gauge theory."
A paper published soon after, "Limit on mass differences in the Weinberg model", by M. Veltman in Nuclear Physics B, Volume 123, Issue 1, 16 May 1977, uses the same term, but says "the so-called standard model". Thus, Veltman uses the term, but prefaces it by "so-called", indicating that the term was new and not universally accepted in 1977.
By the next year, however, the term was on the way to being accepted. For example, in the review paper, "The geometry of generalized quantum logics" by TA Cook, International Journal of Theoretical Physics, 1978. In this article it reads, "The first example we develop is the standard model of nonrelativistic quantum mechanics."
In 1979, Sheldon L. Glashow, Abdus Salam, and Steven Weinberg, received the Nobel Prize for physics for their theory, but the commendation does not use the term "standard model." Nevertheless, at the time (1979), it was widely accepted to refer to their theory as the "standard model" of quantum particle physics.
I believe the long history of building a comprehensive model of sub-atomic matter, all successively named, simply resulted in physicists running out of names after Quantum Electrodynamics (aka QED) was no longer descriptive. Everyone just got tired of coining new names as the theory really stabilized and gained acceptances as The Standard odel.