It was, but it was next to impossible to get a half decent application released on any J2ME phone not to mention the impossible fragmentation (compare to the J2ME beast the Android fragmentation is a sweet tamed puppy).
Java is also installed on a bazillion desktops, numbers don't change the fact that the ui framework is very bad.
Historically applets lost to flash for that same reason
Wasn't is stuck on Java (the language 1.1)? Any Java developers who came in at 1.2, 1.3 or 1.4 would have had to re/un-learn how to do certain things they took for granted.
>Mobile: wasn't Java ME on a bazillion feature phones?
Yep, because there wasn't anything else. But it was painful, slow in terms of progress and incomplete (JSR297 - they are still working on 3D graphics API standardization). And hey no one liked it and knew it far as I can tell - talk real fragmentation.
It may have been on them in some sense, but it certainly didn't have much of an impact there. People didn't write apps for those phones in any numbers.
The world wouldn't look very different today if those phones had run a completely different stack. Or even if it wasn't possible to write apps for them at all.
Desktop: true.
Mobile: wasn't Java ME on a bazillion feature phones?