I Had To Report Antimissionary Divorah To Answers.com Because...

She was using much of Answer.com's Judaism and Messianic Judaism questions to persecute, lie about, attempt to inflame, and derogatorily attack Messianic Jews. Some of the outright lies included lies on even the Law of Return. Divorah's lie about the Law of Return is underlined below.

According to Wikipedia:

Messianic Jews are only considered eligible for the State of Israel's Law of Return if they can also claim Jewish descent.^[26] An assistant to one of the two lawyers involved with an April 2008 Supreme Court of Israel case explained to the Jerusalem Post that Messianics who are not Jewish according to Jewish law, but who had sufficient Jewish descent to qualify under the Law of Return, could claim automatic new immigrant status and citizenship despite being Messianics.^[145]

The state of Israel grants Aliyah (right of return) and citizenship to Jews, and to those with Jewish parents or grandparents who are not considered Jews according to halacha, e.g. people who have a Jewish father but a non-Jewish mother. Specifically excluded were any “person who has been a Jew and has voluntarily changed his religion.” An Israeli Supreme Court decision in 1989 ruled that Messianic Judaism constituted another religion.^[146] However, on April 16, 2008, the Supreme Court of Israel ruled in a case brought by a number of Messianic Jews with Jewish fathers and grandfathers. Their applications for Aliyah had been rejected on the grounds that they were Messianic Jews. The argument was made by the applicants that they had never been Jews according to halacha, and were not therefore excluded by the conversion clause. This argument was upheld in the ruling.^{[145][147][148]}

Yes, the majority of Jews are offended by Messianics who are Christians, not Jews. This is supported by the fact that the Law of Return, which grants automatic Israeli citizenship to Jews and even the descendents of Jews (at least 1 Jewish grandparent), was modified to specify that Jews who become Messianics are not eligible to apply for citizenship as Jews. 

This being said, in the majority of Jewish communities around the world, when a a person who is born a Jew becomes a Messianic, it is met by sadness and pity by the rest of the community. This is because the individual is seen as having cut themselves off from the Jewish community and having renounced his or his path to HaShem (The Creator). There is always the underlying hope that these individuals will eventually find their way back to Judaism though.

As for Messianic organisations such as "Jews for Judaism", they are unanimously despised by all Jewish communities around the world.