Bigocciput

I have a 2005 naked 650 with only 390 miles garage kept. A month ago I noticed that it would not start, so after trying the usual things I took it in to the dealership. When I opened the tank and actually looked into it, I was surprised to see rust caked all over the on the inside of the tank. It was absolutely disgusting.

I have owned the bike for 11 months and yes, I realize I should ride it more but my job and schedule has prevented me from doing so. Right now I am in for a "tank acid wash" and new fuel pump to get it working again. My question is how can this happen? The service tech related that this happens if it sits for any lengthy period of time without a full tank. I do not buy this reasoning. I have had lawnmowers, pressure washers and chain saws that have sat for 2 years without any rust in the tank. In addition I owned a new 1999 GSX 600 without a rust issue and similar low usage. Could I have received a tank made with some inferior steel? Any help would be appreciated. I am going to call Suzuki Corp. on Monday to see what they have to tell me.