Orbital flight vs suborbital flight is a bigger step then you might think. For orbital flights the vehicle is traveling at least 28,000 km/h where as to reach 125 miles above Earth, a suborbital vehicle only needs 6,000 km/h. This can dramatically effect the survivability on reentry. Orbital and sub orbital flights are very different.

Given the uncertainty around heat tiles (and the impact on rapid turnaround) plus the sheer size of the rocket, it seems like a huge step to this ignorant observer.