Wow. Great arguments.
This sort of reminded me back when teams with great sponsorship and dinero ('haves') were able to get their own portable machine shop for competitions. If something needed repair, the team simply went to their trailer and were able to work on it with their equipment. I felt FIRST was right in saying that it was an unfair advantage at competitions for teams to do this, and that the only way to allow this, is if you opened up that portable machine shop for all teams at competition. And I know that some teams, in fact, shared their equipment which is really nice of them.
Back on topic. I feel that FIRST should not put too many restraints that would actually hinder a team's ability for students to learn more about math, science, and technology. However, I do believe that FIRST does its best every year to make the game as fair as possible, to quote, "... to make jumping on the train a bit easier." Even though team's are not created equal (equal experience, equal sponsorship, etc.) they do have the same problem, the same kit, and the same deadline. I also believe that it is important for each team to look at other team's "solution" to the same problem. Furthermore, it is important for people to congregate and share those ideas with one another, in order to better appreciate everybody's "solution" and to learn more ideas, techniques, and information to make their "solution" more effective.
So does making a practice robot make students understand their robot better? Maybe so depending on how it is used. I cannot honestly say at this point. But our team last year built a
a really basic plywood robot during the build season. We used it to allow our programmers to practice and make programs for autonomous and to figure out how to make the sensors (specifically the IR sensors last year) to work.
"But in the end, we all have to remember, it is not about the robots."
Sidenote:
*Keep in mind that teams actually building a main robot and a practice robot are technically building two robots in six weeks. More work for them. The only real problem I see with practice robots are teams that are able to tweak their practice robot after the deadline, and use it as the competition robot instead. As ungracious professional as it sounds, this may tempt teams to do so.