I've seen arranged marriages that have FAILED and I have seen ones that are SUCCESSFUL. Because divorce is such a social stigma in our culture, who knows how many arranged marriages there are where they couple puts on a happy face for the outside world and are miserable within the privacy of their own homes. Similarly, I've seen love marriages that have** FAILED** and I have seen ones that are SUCCESSFUL.
It's not practical to generalize like that. It's not the TYPE of marriage that makes it work. It's the COMPATIBILITY of the couple and their EFFORTS to make the marriage work that determines its success.
The guy in question needs to ask his mom what her real reasons are rejecting this girl before getting to know her. He needs to ask mommy, "Did your marriage fail because it was a love marriage, or because their was a lack of compatibility or other issues?" It takes more than just the word "love" or "arranged" to make a marriage fail or succeed. The words themselves don't have that much power, in my opinion. People in love marriages have to work hard to make their marriage work just as those couples who had an arranged marriage.
If the mom is making this generalization, I think the guy should provide her with some CONCRETE EXAMPLES of love marriages in his family/community that are a SUCCESS. Similarly he should point out to his mom examples of ARRANGED MARRIAGES that have FAILED. Then he should ask his mom "So, mom, do you think that I should marry a girl for YOUR SAKE and be stuck in a marriage where I feel nothing for the girl. And that way all three of our lives will be ruined. But I'll just put on a happy face and live a life of lies. Would that suit you better?"
The guy should reassure the mom that she has raised him well and after marriage he will continue fulfilling his duties of being a good son as well as a good husband. He should reassure mom that he loves her and is not going to "leave her" for this girl, so there is no need to be "insecure" if that is the root of mom's problem. He should have the mom and his girl meet for lunch maybe, so they can get to know each other. He should explain to his mom why he thinks she will not only make a good wife but also a great daughter-in-law. And when the mom and the girl meet, the girl should make a sincere effort to bond with the mom and make her feel comfortable.
And if all this doesn't work, and he's still serious about the girl, then he simply needs to keep persisting until mom can clearly see that he won't accept any other option....and that there's no choice for her but to let her son make his own decisions about who he wants to spend the rest of his life with.
I've seen love marriages where initially the mother HATED the girl, and then after marriage the mom grows to accept and even like the girl.....provided they make the effort to bond.