You are trying to apply Western ideas to the issue in order to understand it. That won't work.
> According to the article, the law prevents first and only Palestinian spouses of Israeli citizens from becoming Israeli citizens,
That is incorrect. The law makes no mention of Palestinian, Jew, Arab, Muslim, etc.
> when love is the sole reason for wanting to marry.
Your idea of what marriage is does not apply here. We are talking about people who have never met. In any case, marriage among the Bedouins is not about affection. Most marriages are between people who have never met. There is a good reason for that - the Saudis don't do this and they have inbreeding problems. The Beduins generally try to arrange spouses (yes, plural) from further away.
> If Israel wanted to prevent citizens from having "third of fourth wives", an acceptable way would be to outlaw polygamy;
Polygamy is already illegal, but again you are trying to apply Western ideas. These people do not recognize the state, and the state leaves marital affairs up to the religious leaders. So they continue to marry multiple wives. Many many laws do not apply and are not enforce with regards to the Beduins and Arabs in general. Mostly this is a non-issue.
> if it wanted to prevent bogus marriages, an acceptable way would be by not granting marriage certificates when the couple don't know each other.
There is no "marriage certificate", again you are applying Western ideas where they do no apply.