Because your credit profile and income do not qualify for a CLI versus their underwriting criteria. We can't provide any more specific information as we don't know anything about either of those. You can provide us with info about your credit profile but the best we can do is guess as we'll never know the details of any creditor's underwriting criteria and can only attempt to use anecdotal evidence.
A lot of people seem to have no luck getting CLi's from Chase. Others do seem to get them. I've never received a CLI on any of my Chase cards but I know I bumped into my internal limit when opening my Freedom as I had to reallocate to open. My wife, on the other hand, has received several auto CLI's, going from 6K to 17K over a couple of years.
The small CLI is yet another indicator that they have concerns with your credit profile.
kleopat wrote:I always make my payment on time and I have 4 other cards and they all have +6k limits
That's great but it's not just on time payments with your Freedom that matter. You entire credit profile and your income at time of consideration matter.
Limits on other cards are not relevant either. Other creditors and products have their own underwriting criteria which are not relevant to Chase.
kleopat wrote:I've called and the CSR said he'd have to run a hard pull, which I declined.
If you want to request a CLI it will be hard pull. It's up to you to determine if the CLI request or the hard pull is a bigger priority. Hard pulls are a relatively small factor and their effect tapers and falls off relatively quickly.
If denied you'll at least have their denial reason(s) as a starting point if you can't assess your own reports to see what might be your issues.