I've only seen two Wheeler & Woolsey films, and it was so long ago that I can't even remember the titles (back in the mid-90's, AMC used to show them, very late at night). It sounds to me like this writer has a special affection for the team, and he's trying to make a case for them being better than they actually are. Those two films I saw were moderately funny, but nothing brilliant or memorable; all I can recall at this point is that one was set in a drugstore, and the other on a Southern plantation. As an aside, those round eyeglasses that George Burns wore in his later years looked exactly like Woolsey's, which he may have meant as a kind of tribute.
I don't think Abbott & Costello are overrated— at their funniest, they certainly rank with the best of the 40's-50's comedy teams. However, I do think they put out too much product and stretched themselves too thin, eventually (Bob Hope once remarked, "Abbott & Costello must be sick, they haven't released a movie this week."). For every "Buck Privates" or "Abbott & Costello Meet Frankenstein," there's a turkey like "Lost In Alaska" or "Abbott & Costello on Mars," which looks like it was shot on a budget of about $18.95.
That whole generation of vaudeville-bred comedians were workaholics, though; it seemed to go with the territory. A lot of the musicians of the period were like that, too. Bing Crosby, Duke Ellington, and Paul Whiteman all churned out an incredible number of records by today's standards, and what's surprising is that so many of them were good. As with A & C, the Stooges and the Marxes also had their share of stinkers, mainly later in their careers when they perhaps should have retired. But they just couldn't do it, one reason being that both Larry and Chico had major gambling habits so they always needed money.
I'd class Wheeler & Woolsey with a number of other teams whose film work just hasn't held up over time, so they've been forgotten: Olsen & Johnson, the Ritz Brothers, and even Martin & Lewis, who also would have sunk into well-deserved obscurity if it wasn't for the fact that Jerry Lewis is still around.