No, the point in having front wheel drive and a V8 had nothing to do with snow/bad weather driving. It was just stupid decisions (as usual) on GM's part. If bad weather was the overriding factor ALL Cadillacs would have had front wheel drive from the introduction of the mid-1960's Eldorado. They did not until the 1980's, and their marketshare slide until the introduction of the Escalade.
And Cadillac's target market did NOT care about front wheel drive as Mercedes, Lexus, Infiniti, and BMW - all rear wheel drive - were and still are far preferred over Cadillac. AND today Cadillac's big sellers are REAR wheel drive. Only Audi is an exception in the league, but that was mainly because a quattro version was always offered and usually taken by luxury car buyers.
It was yet another marketplace blunder from GM, a company that will probably not exist in its current form a year from now.
I doubt it or any other issue is the mechanic's fault. These are just unreliable cars, all riddled with problems.
There are plenty of reasons to have a FWD v8 car. First is that of the ease to build. Makes it much more simple to build the car, cutting costs. Second is interior room, no need to have the big old transmission hump sitting there with you in the car. Lastly is the weather factor, yes it seems odd, but even in rain rear wheel drive cars are dangerous. A Seville is a 4 door car, so having practical front wheel drive is a good idea. Pretty smart. Oh and by the way, Cadillac had front wheel drive wayyyyy before the 80's. Try researching the "Eldorado" which had front wheel drive in the late 60's all the way up to 2003. So front wheel drive is not a "stupid" idea, just something different that has its advantages and disadvantages, like any other setup.
Making the Seville FWD was an incredibly stupid idea. Had Cadillac fixed the problems all too common in the Northstar engines prior to 2002 or 2003 and had they stuck to RWD, the Seville might have been taken seriously. However, it was FWD and couldn't compete with the performance sedans from Germany.
Also, the Eldorado was FWD from '67-'70 and I believe it remained that way until it was discontinued, however until the 90s it did not have enough power much later than '71 or '72 to justify RWD.