Perfectionism in tooling development

It is interesting to know who is guided by what approach when developing a developer's toolkit (CMF, CMS, etc., etc.):

• give the opportunity to do anything (all responsibility on who uses the third-party developer in the trusted domain)
• not to do something wrong (all control on the side of the toolkit, a third-party developer is not included in the trusted domain)

I did not do a survey, I wonder the justification for your choice
')
PS: I will immediately say: I am a supporter of the first option.

UPD : for what cons - the word "perfectionism" or "toolkit" is not clear? ))