Is it normal this kind of comments from reviewers?
It is quite common to get hostile reviews. They are not supposed to be angry, usually it is expected that reviewers stay calm and dispassionate as a matter of professionalism. Sometimes they don't.
If so, what motivate it?
Maybe you have made some glaring errors that are so bad the reviewer was infuriated. Maybe they just really don't like you and decided to find some flaws just to ruin your perfectly good manuscript. Maybe they were having a bad day and felt like taking it out on something. Who knows?
I tend to think that the comments should be objective appreciation of the work and not the author.
Reviewer comments don't have to be objective. One key point of reviews is whether the paper is interesting and important enough to be in that journal. Importance and interest are of course subjective notions.
Likewise, if the author seriously misunderstands the existing theory of their domain, this is a valid criticism. At best they need to rewrite the paper to avoid saying factually incorrect things, at worst their whole work is unfounded. This is of course assuming the author actually did misunderstand something important - oftentimes people say you misunderstand something simply because they don't like what you propose, not because you actually misunderstand it.
How are they perceived by the academic community?
You're not supposed to write angry reviews, this is considered unprofessional even if justified. However, in science many people have strong opinions about things, and these people may like seeing someone scolded over their pet peeve. They may publicly claim they disapprove of the behavior, but secretly support it.
That is to say, don't count on the editor saying "What a jerk, he's bullying the poor author for no reason". He might as well say "He sure showed that fool! Well done!".
Should I respond in any way?
In your example, the reviewer seems to take issue with your fundamental approach. I'm not familiar with the field, but when many competing methods for solving a problem exist, it seems to me perfectly reasonable to examine them all and pick the best one. Of course, if one picks the best by picking the one that gives the results most supporting one's hypothesis, that is circular reasoning with little scientific value. The "best" approach should be chosen on independent criteria.
Since the reviewer says "numerology", I would guess that they consider your approach unscientific in this sense. They appear to imply that you have simply tried several methods until you got lucky and found one that coincidentally supports your claim, not because your claim is correct, but because several of these methods have probabilistic errors, and this one happened to give a chance misleading result. If this is true, then you might want to follow a more rigorous approach to choosing a functional (whatever that is). If it is not true, you should take steps to convince the reviewer that your results are in fact genuine and not coincidental - a classic example can be found in multiple hypothesis testing.
It sounds like you believe the criticisms are unjustified (and otherwise you would probably not submit this question). In your brief excerpt, the reviewer's tone also seems quite hostile, so it's hard to imagine what you could possibly do so wrong that they got so angry. In that case you have a reviewer being unfairly hostile. Your best option is to provide arguments supporting your position, and hope that the editor will take your side. You could complain (to the editor) that the reviewer is being unfair, but that could make you look just as bad, so I wouldn't recommend it (but I also wouldn't recommend against it). A more constructive thing would be to ask the reviewer what you could do to address their concern: If they are sincere, they should suggest a reasonable change that will fix the problem and make everyone happy. If they say something unreasonable like "Scrap the paper, scrap your research, go back to school and retake chemistry 101" then it will be obvious to the editor that they are biased; even a sympathetic person will be put off by such arrogance.