I see your point, the problem is that if you don't do a road show, then no fund is going to invest in you, with google/facebook hyped companies excepted.
With out an institutional investor( Buy side) your stock will have a hard time getting any traction.
If you're offering a small fraction of the outstanding float, you don't need an underwriter because you've elected to reduce your risk. If markets are unfavourable, you raise less. Oh well. You've kept plenty of shares to try again next time.
We need to get over this "go big or go home" mentality.