I am a big fan of education and believe everyone should get as high a qualification as possible.
If you are sensing a 'but' coming up then you are right. Not too sure where you are but university education in US is quite a financial burden. As an aside I believe that the government should further subsidize higher education. Undergraduate studies cost a lot even more so than graduate studies since many top schools offer subsidies some even guarantee $10,000 no matter your financial status just to attract people. Which brings us back to the following questions:
No matter how severe one's learning disability is, the question is can the person with perhaps help and determination overcome it such that they are not disadvantaged from the rest? Or rather to be more precise, can the person graduate from the program in question? If the person fails to complete the program, he may end in a worse position such that he have a significant debt burden.
Another side point to be made is what is the expected increase in income following a successful completion of the degree? This taking into account the degree opening up previously closed roads and such. Although I am not in favour of the next argument, it has been said that if the person know their career path and that for some reason or other education does not really add that much value then it may operate as another strike.
Therefore in conclusion, rather than looking at what other people with similar learning disability did or did not do, your friend should just focus on themselves and ask the simple questions,
1) "Do I think that I can successfully complete the degree, notwithstanding my learning disability?"
If the answer is in affirmative proceed on to 2
2) In a general terms based on your own expectations, do you think that pursuing the particular program will add significant value, such that it is more so than both the cost of the program and time taken off current job.
If the answer is in the affirmative then one should take the program. If the answer is in the negative proceed to 3
3) Do you think pursuing the program will bring significant non-tangible factors such as education offering new opportunites or allowing one to expand one's horizon?
If the answer is in the affirmative then one should take the program. If the answer is in the negative then one should really seriously rethink about the situation focusing on a) desired career, b) cost of program, c) value added.
Remember all this is only applicable if your friend have to pay a significant amount for the education. If cost is not a problem then he should go. I am assuming that your friend does not have a well paying 6 figure salary job currently that will not wait for his return because if that is so, everything needs to be reconsidered.