As others have said, searching for a dojo or having doubts about the teacher's skill would be good reasons for checking out other dojo/styles. And there are those out there proclaiming their style is the "one true way", etc.
In my own case, I started learning karate-doh and aikido 20 years ago. After some time, I felt reasonably comfortable with karate-doh, but never felt comfortable in aikido. Actually, I never felt like I knew what I was doing. Ten years later I found myself in Japan, in an aikido dojo where a friend of mine studies. From the very first technique, I couldn't move an inch. It rocked my martial arts brain. I had studied aikido for 10 years, but it wasn't aikido, just a facade of aikido.
Having studied for some time in Japan now, I have more of an idea what was missing and why I couldn't move. But how does someone who knows nothing ascertain what is "real" aikido and what is "dancing"?
When I first started studying, there was no Internet, not even e-mail, and I had never heard of aikido. It was what they were doing next to the karate-doh space and I joined them. I have recently done the google search for aikido, and I am utterly amazed at the amount of information out there. People should by all means use it and shop around for a dojo/teacher/style that suits them. Knowledge is power.