Personally, I think these questions should be allowed and for a number of reasons I want them to be allowed.
Why should they be allowed – the objective part
Questions like this are in line with the spirit of the site: this site is for the users of Mathematica and for the problems they encounter while using Mathematica.
Package installation problems are ...
According to https://mathematica.stackexchange.com/help/on-topic
Some kinds of questions are considered off-topic:
Questions on Wolfram Alpha (but questions on using Wolfram Alpha within Mathematica are okay).
And following advice on Sending WolframAlpha questions to WolframCommunity you can try on community.wolfram.com.
How user-friendly any particular part of Mathematica appears to any particular new user is intimately bound up with the previous programming experience of that user. That means the kind of question you are proposing will get very different answers from users with different backgrounds. Thus, such a question would have to be closed as "opinion based".
I believe that the Mathematica chat room is the appropriate place to discuss your concerns.
As Kuba noted your question is both too broad and opinion based, two canonical reasons to close a Question.
I think that Wolfram Community cannot be expected to be nonpartisan so I wouldn't personally ask such questions there.
This question is good example of one that should be closed because any answers can only be opinion-based. However, I will give my opinion.
The design issues brought up in this question are important ones, but no general answer can be given that will be the right answer for all Mathematica projects. Mathematica is simply too big a tool box, applicable to too ...
Posting my comment as an answer, but don't take my opinion as fact:
I personally think it would be on topic, since we do get questions like that about Matlab (edit: turns out, we do not get exactly this type of question, but we do get IMO similar questions). However, I don't think you'd be broadly successful in getting answers.
Perhaps better to ask ...