Sorry if I come across as too didactic.
Discipline is the biggest differentiator between successful and unsuccessful candidates. Time and again, we see too many smart people fail (or dropout) due to lack of discipline. We would want all our users to pass and hence we’re doing some unconventional (unpopular) things such as limiting the daily questions. Actually it was easier for us to let people choose the number of questions (just like Schweser and Wiley do) and be done with it. We won’t have had to code extra and explain to so many users (this is probably the most FAQ and worst explained feature on our website).
If we allow unlimited questions or let users choose the number of questions, people procrastinate and put off practice until the end of the week, month or even worse till the last month before the exam. They take it for granted. They know they can always go online and get as many questions they want. That’s precisely the wrong behavior. To discourage that we’re trying to create a use ‘em or lose ‘em mindset. Hope I’m making sense.
BTW, the number of questions you get in a day is also adaptive - they increase with your activity and as the exam draws nearer. For instance, if you’re currently on 12 per day and you practice for at least 5 days a week, it’ll go up to 18 for next week and so on.