No, what it actually shows is that everyone works in different ways and some are more deadline-driven than others.
I had two terms to complete my dissertation. I wrote the whole thing in four days and handed in the hard copy 15 minutes before the deadline. I also handed in all my coursework essays to similar timescales for the duration of my degree course. In most cases we had to hand them in at 9am, and I pulled all-nighters to get them done.
And guess what? I also got a 1st.
People all produce their best work under different conditions. That's why some people perform really well in timed exams and tests - it's the ticking clock and the need to just do it now that spurs them on to produce their best work.
Once your actually working handing in projects and data in with 10 min to spare when you have a deadline will not go down well.
It depends on the kind of job you do. For your kind of role, then I'm sure your approach is best.
But I work in a field where we have to turn round very accurate and well-written work at very, very short notice, so being able to get stuff done in a mad dash at the eleventh hour is an absolute must. People who are more comfortable with a lot of pre-planning and finishing things days before they need to submit them really, really struggle in my line of work and don't perform well (plus it's horribly stressful for them).
When we recruit, we get candidates to complete a timed task at their interview, based on material they've never seen before - if we asked them to plan or prepare something in advance, it wouldn't test the skills we need to see from them.
We're all different. What's right for you isn't necessarily right for everyone.