I don't think that's plausible. More likely the match was 50% of the first 6% of salary employees deferred. That would require an employee to earn $300,000 in order to see a maximum $9,000 match. Now an employee can receive the full match merely by deferring the maximum amount, regardless of their salary.

6% refers to 6% of salary, not 6% of deferrals. 401k contributions are measured in terms of percentage of pre-tax salary contributed, and the match is based on that.

Under the old scheme, you had to contribute at least 6% of your pre-tax salary to get the maximum match, which was 50% of whatever that value was. In other words, the maximum match was 3% of your salary, and you had to be contributing at least 6% of your salary to get that. Now, anything you contribute gets matched at 50%, regardless of what your salary is.

You are completely wrong.

Pretend I made $100k, contributed $6k -- they matched an additional $3k into the account.

The match was considerably more than $540 @ $18k.

Source: I work there.