I was going to say it was tongue in cheek ... but maybe this thread would end up in JetBlast then
Seriously though, it's a Bulletin Board, not an English exam.
Spelling does not in anyway affect how good a controller you are. Lots of people are simply natural at picking up the skills and characteristics required to make it in the industry. Others require to put a bit of effort in to get there but do so in the end, none of that effort requiring them to brush up on their spelling. And a small proportion of people struggle and never make it, regardless of their spelling prowess.
There are written exams along the way, but I've never seen anyone marked down because the spelling or grammar was technically wrong in places. They fail because they don't know the answers. There is also much more emphasis placed on practical and oral examinations as you progress towards being let loose as a licenced and valid controller. And that's exactly where the emphasis should lie.