I think it's going to depend on a lot on your markets.
For example, in the UK I believe there's exactly 1 BREW handset available on the market, and it's fairly true to say that no one has even heard of BREW. The handset manufacturer and supplier refuse to provide any technical support to BREW developers, and removed some of the BREW developer functionality in the second revision of the device. (I'm talking about the Skype handsets released by '3'.)
In Japan, BREW is still quite popular, with many/most of the handsets shipped by KDDI (one of the top 3 carriers) supporting BREW - though this is generally BREW 4, whereas pretty much every other geography is still on BREW 3.x and seems unlikely to migrate to BREW 4 due mainly to internal Qualcomm politics over BREW 4.
I don't know how well any after market BREW apps do in the Japanese market, but certainly there's a few people around who make a decent living off selling BREW apps to the OEMs to preload onto the phones (this approach also means you don't have to go through True Brew Testing, though you still have to go through any OEM/Carrier testing).
However, Android has a big presence in both markets, as does the iphone. Both have much better app stores (than both BREW and J2ME), and generally lower barriers to entry.
BREW handsets are (as a generalisation) cheaper than android or iphone handsets and are generally lower spec devices, often without touch screens, and often with much smaller screens. (Though Android is slowly moving to lower spec devices.)
The above is generally fairly factual, I think you're also asking for an opinion: My opinion would be that BREW, when it was released, was really quite novel, and did in some geographies achieve a wide market share, and did have quite well setup infrastructure for getting apps onto the phone. In many ways it is quite old fashioned now though, as it is quite a closed system that is difficult for newcomers to gain traction in, and the OS itself doesn't provide an experience that's on a par with Android or the iphone (or other iOS devices). Given that I expect it's not really gaining any new developers, but there are a set of people around that already know the platform and will continue to make money from it, though it's really in a decline now, as it failed to achieve mainstream popularity in the same way iphone & android now have.