There are no ideological reasons.
https://github.com/golang/go/commit/dd64f86e0874804d0ec5b713... "Generics may well come at some point."
https://golang.org/doc/faq#generics "A language proposal implementing a form of generic types has been accepted for inclusion in the language. If all goes well it will be available in the Go 1.18 release."
One of the language designers explaining the motivation for adding parametric polymorphism to Go: https://www.youtube.com/watch?v=RIvL2ONhFBI&t=1064s
Explaining the benefits of generics: https://www.reddit.com/r/golang/comments/jditu9/what_do_gene...
From the Featherweight Go paper: https://arxiv.org/pdf/2005.11710.pdf "Recently, the Go team mooted a design to extend Go with generics, and Rob Pike wrote Wadler to ask: Would you be interested in helping us get polymorphism right (and/or figuring out what “right” means) for some future version of Go?"