> the guys with hundreds of employees who paid us hundreds of thousands of dollars in support rarely called us (or if they did, they had actually competent IT staff we could work with)

These are all related.

Customers who are successful businesses tend to have money, and competent employees who solve many of the problems themselves. Customers who are not successful tend not to have money and less competent employees.

This is why so many people recommend startups and contractors to raise their prices - not only do you get paid more, but also you filter out less competent customers.