10 minutes into the mash on my first brew on my electric rig, someone drove into a transformer and POOF! No more power. The whole town was "dark".
So I wrapped my kettle (eBiaB) with an old sleeping back, RDWHAHB.
When the power came back on 30 minutes later, I'd lost a whole 3 degrees.
Initial startup costs can be steep, but if you space them out over a year, they are negligible. For a 5 gallon batch, I'm estimating that I use less than $1.00 in electricity (we have ridiculously cheap electricity up here). I'd have to get 20 batches out of a single 20# LP tank to even come close to the same cost. My average has been 4 or 5 batches from a 20# tank... so over the course of 1800 or so gallons, the rig will pay for itself on energy savings along. While that's not a feasible argument in favor of moving to electric, if you assume 20 5-gallon batches (100 gallons per year, which is usually the "limit" allowed by states), you're looking at Over $400 per year savings. That number might help with the SWMBO. Plus... you can get a lot of ingredients for $400. I built my deck for $400.
I do miss brewing outside on a warm sunny day. However, I LOVE having a dedicated brew space. There is absolutely nothing else in that space that isn't directly related to brewing. That means I don't have to spend an hour pulling stuff off various shelves in the garage, from the basement and the kitchen. I know my electrical work is solid. And If I want to "travel" to brew, I'll take my Blichmann burner and an LP tank with me, so regardless what happens, I have an LP backup (and in the meanwhile, the SWMBO uses my Blichmann for canning... win-win).
This will always be a Ford vs. Chevy debate. Both systems do the same thing: they make beer. I catch crap from on of my LP "purist" buddies about how I'm now "lazy" because to brew a batch, all I have to do is "push a button"... but I think he's just jealous.
In my eyes, there just isn't a downside to moving to electric.