Yes it is, so he either does have a learning difficulty (as OP suggested) and is hobbled by it or he has been let down by the education system or he’s lazy and stupid. ( might be some other reasons, too) As a result his motivation (if he had any) would be neither here nor there. Some people can’t read and write English because… they can’t. It’s that simple.
Whoa there, horsey. I was making a general opening statement - not a rebuttal to a sentence you never wrote. In another reply I went into a little more detail. My main point was that if it wasn’t because of a learning difficulty then simply “motivation” isn’t always enough. A lack of facilities ( No libraries, no literate family members, no internet connection, inadequate education etc. ) could be a factor.
On a side note, do not ever accuse me of being a septic again. There’s literally dozens of people on the internet that aren’t USian - but I understand it’s much easier to throw labels on people who don’t pander to your every post.