Sorry, have to disagree with you there my friend. The Servisair station where I worked (regional airport) has consistently recruited pilots fresh out of training, or guys looking to start. I was one of 3 in a team of maybe 20 when I started with them, and they've had at least another 5 or 6 pass through since I left. It is no handicap at all.
As for whether or not it is looked on unfavourably in your flying career, I would have to say definitely not. It may not necessarily impress, but it certainly won't disadvantage you. All the flying dispatchers I knew are working for a variety of airlines, and we had the massive disadvantage of leaving training in the months following 9/11. Strangely, the last 3 of my course mates to get airline jobs were all FIs. Make of that what you will.
I agree to a certain extent with the statements about building contacts. London is certainly an exception to the rule, but at regional airports, or even the larger internationals with a high number of regional airlines (MAN, BHX), you have the opportunity to get yourself well known amongst your regular crews. If you get a good name for yourself as a hard working and capable dispatcher, it can definitely work in your favour. It may not help get you that first job, but your crews will remember you and this industry is unbelievably small. You just never know who you'll bump into again. My next move is almost certainly going to be back to the airport where I was a dispatcher, and to our main client. I'm still in contact with many of the crews who happen to be friends now, and I intend to use that to my full advantage when the time comes.
If nothing else, hard graft, crap hours and the minimum wage will ensure you appreciate flying for what it is. I'm constantly disappointed by the greedy whingers who think they've been hard done by in this industry, when we get paid a small fortune for effectively doing very little on a day-to-day basis.