People don't like waiting for mass transit, but what they really hate is waiting with uncertainty. I'm ok with waiting 10 minutes for the bus if I'm reasonably sure it's going to show up in about 10 minutes. It's the nagging concern that 10 minutes might actually be 20.
More frequent service is desirable for the obvious reason that it reduces average waiting times, but it also reduces the possibility of an extra long wait due to equipment failure or other problem.
Real time information is really a big help in this area. My local transit authority's real time bus location service isn't perfect. The GPS only gets polled about every 3 minutes, and there are occasionally ghost or missing buses. It does provide a decent enough clue about what you can expect, and especially for bus lines without super frequent service (I'm looking at you, #64), it makes the experience much better.