Last I checked, support was missing for the newer ALB load balancer on AWS. That is a hold up for some as the older ELB doesn't scale as well, and needs "pre warming".
kops can set up an ELB for HA apiservers, but I think you're primarily talking about Ingress for your own services. We don't actually take an opinion on which Ingress controller you use, so you can just choose e.g. https://github.com/zalando-incubator/kube-ingress-aws-contro... when your cluster is up.
Maybe kops should use ALBs for the apiserver, and maybe k8s should support ALB for Services of Type=LoadBalancer. Neither of those are supported at the moment, if they should be then open an issue to discuss. (Even if you're going to contribute support yourself, which is always super-appreciated, it's best to start with an issue to discuss!)
Yes, it's not specifically a criticism of kops. Supporting ALB as an ingress controller seems to be the direction, with the coreos contributed code the likely winner.[1]
Thought it worth mentioning though, as the older ELB+k8s isn't great, and because the ALB support hasn't shaken out yet, a cluster created with kops could be suboptimal unless you address it afterwards.
I assume once it all shakes out, kops would support whatever the direction is.
