It's one of the few places in the Caribbean, along with Utila, that this can be done without spending all of one's trust fund.
Many people want to become DM's or OWSI but need to build up the number of dives. experience and confidence level first. This requires access to guest divers in need of such assistance. Cruise ship divers and casual divers that walk into day-dive operations are great learning tools for your education.
The Bay Islands can be comparatively inexpensive to live-in while you are doing this training. Many people of the age who are likely SCUBA professional candidates enjoy the lifestyle and atmosphere of the West End- if not there then they might like Utila town instead.
It's warm, there are pretty fish, living costs are low... for the Caribbean, and there are similar other young people to flirt with at night. Younger folks, those with need of logging dives- it seems to work best for them. Older folks don't generally slot-in as well, but it depends upon attitude. There are other options, here in the US as well as on Roatan- where older, more mature divers can strap-in and pound through the courses very quickly~ not much night life on the schedule. When you balance out the costs considering duration of stay with housing and food, you'll have to be the judge.
The easy going Bay Islands "stay awhile" program? It works for many.