I'm not trying to antagonize anyone or going against dev and his awesome work. I'm using the miner and I'm ok with the fee. I just express my opinions as everybody else.
Of course it takes time to recover after NOT finding a block. The number of blocks that you find with your hashrate is an average, sometimes you hit blocks faster and sometimes slower. The more hashrate, the less variance. That's why slush invented pool mining, to reduce the variance. You get a smaller chunk of the reward but more often. With my 300 mh/s I should find a block every 1.54 days in average. If I miss a block because my rigs are off my chances of finding a block again are exactly the same but remember I will find in average. Time keeps running but blocks don't come, so average decreases. In your opinion it doesn't matter if I hit a block or not? Then try to mine with your rigs off.
You should repeat school exams about probability.
If You flip coin on head doesn't mean that in next flip chances to get head are lower. Therefore, if You hit block during devfee period, this doesn't changes probability of hitting blocks the rest of the time. As all other said, chances of hitting solo blocks are lower exactly for the percentage (1-2%) of time mining for dev.