My first reaction is the same as Deborah's, FWIW. I almost posted but didn't. Glad someone else took up my slack!

The 'of/for' confusion is pretty typical of a trend that's been irritating me for years. A phrase gets misremembered by someone in a popular film or broadcast (as in this case), or it gets mixed in with another phrase under similar circumstances, and ten years later people give you funny looks when you try to explain that it's either "in regard to" or "as regards", but not "in regards to".
The trend is most commonly seen in people who wish (often quite unconsciously) to appear more educated than they are. (The reasons behind that are a whole 'nother kettle of sturgeon.)
In this case I wouldn't be at all surprised if the line had been written that way. I'd like to think it was a deliberate commentary on the character's wit, but I'm probably dreaming. I expect that someone has remembered something like "what kind of man..." and unconsciously crossed it with the known construction "poor excuse for x..."
...and produced another step in our slow muddy slog towards cultural incoherency in our own language.

Honestly, I blame mass media. Hardly late-breaking news, but there it is. There's a levelling quality I see in the effects, wiping out regional dialects and creative personal expression alike.

I agree of course that "poor excuse for a man" would be the according to Hoyle way of doing it. But I wonder . . . not having seen the originally referenced show, I can't speak to whether it evinces any other stabs at poetical language . . . but I kinda sorta like this. I wonder if it hits peoples' ears wrong simple because it's too close to a standard, less interesting and poetic usage. What if it were . . .

that shadow of a man

that misapprehension of a man

that aspersion of a man

that shudder of a man

that affliction of a man

that cop-out of a man

that whisper of a man

I'm home from work on NyQuil, I could do this all day. But you get my point . . . sloppy writing or nonstandard poetic usage? To quote the great David St. Hubbins, it's a fine line between clever and stupid