Objections

- What's to be said against preregistration? -

Potential arguments against preregistration are mainly found in discussions between supporters and opponents. A subjective summary of the general pros and cons of preregistration is shown in the following table:

Preregistration takes away the freedom we need in research.	With and without preregistration, scientists are free to explore what and how they please. Preregistration only ensures that exploratory studies can be identified and thus interpreted as such. Thus, at most, the freedom to be non-transparent is taken away.
Preregistration will not stop fraud.	That is correct, fraudsters can still illegally falsify their research and cause damage. However, preregistration could make this more difficult as well as explicit. Most importantly, it is a valuable tool for honest scientists who want to produce high qulity work and avoid implicit bias.
Preregistration is too cumbersome.	As a rule, preregistration does lead to extra work. For the reasons previously mentioned, this work is worthwhile on a personal level as well as for the sake of science as a whole. In many cases, the work on preregistration is also beneficial to the later publication and shortens the process of analysis through increased focus on planning. Therefore, preregistration should be viewed as an investment that pays off in the long run. In general, researchers continue to preregister once they have tried it.
Preregistration rules out reacting to unforeseen occurences adequately. A research project requires flexibility.	In accordance with the freedom of scientific research, preregistration is not intended to act as a prison. Reasonable changes and reactions to unforeseen problems are still welcome. Preregistration can also be used to justify such changes in later publication.
Preregistration allows others to steal my ideas.	Normally, preregistrations can be hidden from the public for a certain time (e.g. 4 years at OSF).Through this embargo option, the preregistration receives the necessary time stamp, but cannot be viewed by third parties.

As an example, in the field of consumer psychology, but concerning general aspects, the following scientific dialogue can be found:

Krishna (2020): https://doi.org/10.1002/jcpy.1211
Simmons et al. (2020): https://doi.org/10.1002/jcpy.1208
Simmons et al. (2020): https://doi.org/10.1002/jcpy.1207
Pham & Oh (2020): https://doi.org/10.1002/jcpy.1213

Summary of this dialogue:

Pham et al. (2020) provide an extensive list of arguments against preregistration. The authors' positions are essentially based on the assumptions that preregistration is neither sufficient nor necessary for good science. Both may theoretically be the case, without this being a reason to refrain from preregistration. Therefore, they also discuss alleged risks associated with preregistration. There is a response to this publication by Simmons et al. (2020), in which the individual arguments are analyzed and partially accepted but not acknowledged as valid objections against preregistration:

Simmons, Nelson & Simonsohn, 2020

Another interesting dialogue on the topic can be found in a blog post between A. Ledgerwood and R.S. Shiffrin (2018). This is more about the question of whether scientific work has not always been post-hoc and exploratory in nature, and whether that is not a good thing. Again, this is not a direct argument against preregistration as a helpful tool for confirmatory research.

In general, there is opposition to preregistration, but at the same time there appears to ba a lack of valid arguments against it. As long as preregistration is seen as a helpful tool for honest researchers and limitations are recognized, everything is in favor this practice.