Hello Wiseman,
I am sorry hear about your experiences. While I am going on internship now, I was once in your shoes and can remember how demoralizing I felt afterwards. It is rough, but like you said, many people have this experience. I wouldn't let it dissuade from reapplying in the future.
Like yourself, I applied straight out of undergrad my first time around. I received only one interview after applying to 12 schools that were highly competitive. The sole interview went horrible, and needless to say, I went without an acceptance.
Afterward, my mentor and I did a postmortem on my application in an effort to identify what went wrong. The goal was to help me improve as an applicant and get accepted in the future. We identified several weaknesses, which looking back, I wish I would have thought about more clearly. I will share what I think got in my way. Perhaps, this will be helpful in reviewing your own application. To note, some of the concerns were mentioned by the previous posters, so I apologize for the repetition:
1. Competitiveness of the programs: Take a look at the acceptance rates for each program to which you applied. Is there a distribution of programs with respect to the number of applicants per year, acceptances, etc.? Also, are you limiting yourself in terms of geography? I limited myself in terms of geography and the degree of competition was not balanced. This was the first main flaw my mentor and I identified when reviewing my strategy.
2. GRE Scores: In my case, I think this may have been the second biggest hurdle, as I am terrible at standardized tests. I suggest that you compare your scores to the averages reported by the programs to which you applied. Do your scores meet or exceed the mean that is listed for the Verbal and Quantitative sub-tests, both individually and combined? Are you weaker in one area over the other? While my combined score was relatively similar the average of combined scores at the programs I applied to then, my quantitative score far outweighed my verbal score. The discrepancy was high enough to raise a few eyebrows and probably led to some concerns.
2. Research Experience: While two years is a solid number for any applicant, it is not only the quantity of time that is important. Did you present any posters or papers at conferences? If so, how many? Have you authored or coauthored a paper? If so, how many? What were your responsibilities in the lab you worked in? What type of lab was it? Does the experience you gained and/or the nature of the research match with the research interests of the POIs you contacted?
In my case, I did cognitive neuroscience research. While I had several posters, one presentation, and coauthored two publications (i.e., my biggest strengths), these experiences had no relationship to treatment outcome research for affective disorders, my true passion within the field. The lack of perceived goodness-of-fit was a major weakness of my application.
3. Letters of Recommendation: Who wrote these letters for you? How well do they know you and the quality of your work? Were some just professors you had for a class, versus people who mentored you in some way as a student and/or employee? In the case of the latter, was the job related to psychology?
You want to have glowing letters of recommendation from people who know you very well, for an extended period of time, and that can speak to your qualities as a future psychologist and readiness for doctoral level work. In my case, two were very strong letters from professors who knew me extremely well (~3 years), while one was from a professor who I took one course with - big mistake. I went this route because that one professor had published in areas relevant to my future interests. Yet, he truly could not speak to my character or my research abilities - there was not enough of a relationship. The letter was fine, just not stellar. I think this set me back a bit. I don't think it was the biggest hurdle, but it was an area of potential weakness that I did not consider until well after the fact.
4. Quality of Undergraduate Institution: I am not sure where you graduated from, but in my case I think counted as a strike against my application to some extent. I went to a very small, relatively unknown, state college. Even though I had a 4.0 GPA (i.e., a major strength of my application), the lack of reputation for my alma mater in conjunction with the lower Verbal GRE sub-test score probably made much less competitive. This is especially true when there are sure to be applicants with similar scores from more well known institutions.
5. Clinical Experience: Have you had any experience working in direct contact with clinical populations? If so, is it related in some way to your future interests? While I had some clinical experiences (i.e., a moderate strength of my application at the time), these experiences were much like my research background - completely unrelated to my future interests.
In an effort to address these concerns, I decided to work in a clinical setting for year while continuing to volunteer in my former lab. I used this time to weigh out my options and come up with a plan.
In the end, I decided that the best course of action FOR ME was to get a Master's Degree. I thought this would allow me to gain research experience more relevant to my clinical interests, display my aptitude for graduate level work, garner a degree from a more well known institution, and afford me the opportunity work part-time in a clinical setting with a population that was more relevant to my goals. It was very difficult and time consuming, but it worked out. I should mention that friends of mine, who had similar experiences with their first round of applications, found paid RA jobs in clinical research settings after they graduated. They ended up being accepted as well and their route was much shorter and economically sensible than my own. I know more people that went this route and found success. I would consider both as options, in addition to whatever ideas you develop on your own.
I hope this information is helpful to you. Best of luck in your endeavors.