Since this is Meta, and the request has been made, a meta-review (review the review) may be appropriate...
Is this an OK behavior on this website? I'm not so confident about putting in time for not-so-sugary-but-I-believe-honest reviews now.
Is it OK for a user to delete their question? Yes, absolutely. It can be irritating, but it is their prerogative.
Should you lose confidence about putting in time/effort for reviews, no, but....
... I have some real sympathy for the asker in this instance. You were harsh. In my opinion you were overly harsh.
In general, people coming to CodeReview will/may have poor confidence in their own skills, and may have 'psyched' themselves up to post their code here. This may just be the pride and joy of their past week's labours, or may be a kid trying to be better than their school mates...
A harsh review is appropriate when the code is below expectations. On CodeReview, it is very hard to set the level of expectations appropriately. The only mechanism is the beginner at the moment, but, in this case, it was not used. Still, you have to give some benefit-of-the-doubt.
Still, it is apparent (in my opinion) that the 'experience' of the asker is 'immature'.
( EDIT: I see this answer you gave to the same user here: A package for basic utility functions Here your tone is completely different )
Your review would have upset many people I know who are professionals, never mind beginners.... In summary, your review is:
I am going to be very harsh:
- your code is a mess
- it is incomprehensible
- it does not do what it advertises it should (it's not a library).
- the abstractions are a mess
- who needs this anyway (use a different framework) like 99.99% of applications
- "Your code seems to suffer from architecture austronautry."
The only positive thing you say is
Your methods are mostly simple and nice
So, while everything you say may be true, it has only taught the asker one lesson: come to CodeReview to get your code bashed, and feel inadequate.
There are a number of GOOD things the asker did:
- "use strict"
- the code is very neat and well formatted.
- generally good comments.
- .... and that's just from scanning the code, not reading it....
I do not find anything encouraging or motivational in your review.
People are not coming to CodeReview to feel bad about what they've done.... to get "shot down".