I agree Cozumel has a lot to offer. The topside food options are one of the strengths of Cozumel. We do love Cozumel, went there for many many years. However, we have watched it become even busier, and some of the dark side issues are growing more rampant. You cannot walk down the Melgar without being asked if you want to buy drugs. I know this issue is everywhere, but it seems way more obvious in Cozumel.
For us, while we really enjoy shore diving, Bonaire doesnt have anything as close for topside. The food is meh at best. It is way less busy, which we like. The diving is good.
We still like both places, and will visit again and dive in the future.
What we like at Roatan, especially West End, is the quaint easy going style. We cant walk down the street without stopping to hug local friends. The food is quite good, with lots of variety. The diving is easy, and while the vis isnt as good as Cozumel, its no current. We pay $35 for a dive, or $70 for a 2 tank. Over 4-6 weeks, that is quite a savings for very comparable diving for the most part. There are dive ops there that offer $25 a tank for repetitive diving.
Most of all, we love all the local friends we have there, and the quaint atmosphere. I think ease of diving factors in as well.
I know, to each his own, but it checks most of our boxes.