The basic answer is that when an certain type of organization gets to a certain size, they hire professional full-time sales people, and those sales people have been trained their whole career on Salesforce, so that's what they're familiar with and that's what they're going to want to use.

I've tried twice to buck this trend at small startups. I was successful in getting the companies to use a lightweight, elegant, user-friendly, not-Salesforce CRM system when they were small (<10 people). And everyone was happy. And in both cases, as soon as the organization got large enough that the professional sales people came on board, they said "what is this garbage where is my Salesforce", and that was that.

This is a VERY hard pattern to break, unfortunately.