This is a little tone deaf and lacking deeper thought. Surface level stuff like x color buttons are ugly is not really helpful. Telling a guy who has been focused on this for months he should spend more time dogfooding - again, not helpful.
What really got me though was complaining that you could not upload a resume. Seriously, give it some thought. Parsing non-structured data in an accurate way is a very hard problem and I would venture getting highly accurate results on 80% of resumes would take hundreds or even thousands of man hours to build a system, getting it on 90% or more could be exponentially more difficult. It simply is not worth the investment of time unless you have a breakthrough technique, and if you have that - well that is your startup, not a job site.
Feedback is awesome, but not everything that crosses your mind is worth sharing.