Indeed you can. But if I want short-term work, I take contracts. If I'm looking for a permanent job, I'm specifically looking for some place that I'll be for years. So it is a bit like marriage in that sense.
Also, it's not a great look on your CV when you've only been at a non-contract job for a very short time.
Spending a bit of time to do research on a job, versus going through the hiring process, possible relocation, training and team familiarization, and all the physical and mental stress involved - only to find out you don't fit and then going through the exit process.
Also, it's not a great look on your CV when you've only been at a non-contract job for a very short time.