Probably because BTC-E doesn't accept bank wires, well you could send one through interkassa but you'd pay a huge amount of fees. BTC-E only thing I know about them is that I think it's out of Bulgaria, though maybe he just incorporated there and is living in Russia. Either way owner isn't really well known, so unlikely to be trusted with millions per day in liquidity but they're still doing really well anyways. Might as well stay under the radar and continue to make good income with trading fees and avoid mass government problems when you start trading way too much
BTC-E accepts wires starting from $500, just check the options available.
Though wiring from US is prohibited.