If I may rearrange your post a little (and please tell me if I am misrepresenting your view, because that is not my intent):

Employers may abuse employees in terms of wage, and this has been seen in the past.

Corporations have a stronger negotiating position than many (most?) potential employees, and one of the primary ways this is manifested is in the following manner:

When a person faces the choice of no-income (substituted for your use of "job") or income, the choice of income is near-universally better.

I think the conclusion "we need a minimum wage" is too strong. This is not the only way to provide bargaining power to potential employees. By way of proof I offer an alternative means to a minimum wage, namely some form of subsidy given to all humans. This type of arrangement is often termed a universal basic income and there are numerous specific implementations which have been proposed over time.

It seems that having identified a problem (employees may be faced with a raw deal when interacting with employers), we should look for multiple (though perhaps not all - exhaustive searches can be expensive (keep in mind time is a resource and that opportunity cost is always present)) approaches and weigh their positive and negative characteristics.

To do otherwise seems but a parody of rhetoric and reason, captured well in the "Yes, Minister" scene linked below[0].

I do not propose UBI as the only alternative to a minimum wage, or even as the best of all possible options, only to suggest that your obnoxious people may perceive both the problem you have posed and an alternative solution that they believe to be better than the one you propose.

The way you present your argument seems to me to assume that those who disagree with you must be ignorant or malicious. Starting a conversation with either assumption seems fruitless. To accuse (even obliquely) a person of ignorance and forcibly try to educate them is, in my experience, an exercise in insult and folly - even if a person is ignorant, an aggressive teacher is not likely to be listened to. To engage a malicious actor with reason and education seems simply folly - if they understand the problem you pose and enjoy the ill it brings to people, then you have nothing to gain by explaining that negative effect. It seems to me that such a rhetorical approach is geared to identify friends and foes, group these people together, and allow the speaker to dismiss the latter.

You have the unlucky position of being the first in this thread engaging in such a way. I see it equally among those that I imagine you would side with and those you would side against. I have the unfortunate disposition of occasionally ranting as I have above.

I hope that if you've stayed with me this far that you are, in fact, interested in reasoned discourse and willing to accept some unsolicited advice from an internet stranger who is ornery today. Perhaps you might do better at engaging those obnoxious people by finding common ground - it is usually simple to agree that you are both interested in improving the lot of those who are least well off and that you both agree that certain problems can and do exist. From there it is much easier to find a productive conversation about various means to address the specific problems, and the many positives and negatives of each.

[0]: https://youtu.be/trw1PbQt_Yo?t=11