Registering late is O.K for those who experienced with the push/fold strategy.
late registration is never more profitable than starting a tournament on time because you are missing lots of action when the blinds are low and you can get involved in more hands like speculative hands (small pairs or suited connectors like 78 or 98 on good positions.)
also as soon as the blinds increases you m ratio will be lower and starting the tournament late will make your stack not only below average but also you will become shortstack specially if you register to the tournament 1 hour or more later. so its always best for you to register to the tournament on time or at least before the 5th or 6th level of blinds in deep stack tournaments and before the 2nd or 3rd level of blinds in turbo tournaments.
Not to mention that you can always profit from an early monster.
Imagine getting AA or KK as one of the first hands when a lot of maniacs are still around (this probably is mainly for the lower stakes).
You could profit so much from that.
If you get nothing, you almost don't lose anything with those blind levels and no ante.