Some syntax issues (no function pointers, no lambda, no rich literals, enforcing everything to reside in an object) endears it to Enterprise OO mindset where you want large teams of programmers working "efficiently" - but ultimately a risk conscious and ego driven manager just wants a large team of developers to further their career - and doesn't care how much boilerplate is present or how few lines of code actually do something productive. These are slowly being addressed with newer versions of Java, but it's a long hard road out of hell... and the mental association of Java as enterprise VB is here to stay.

I'd say it's guilt by association with the early years of a java. It reminds lots of people of the bad old days of programming. Getters and setters instead of pure data. Using java objects to hardcode schemas in the middle tier. Horrendeous death by meaningless patterns (form over function). Gigantic libraries configured by XML (how can you take a modern language seriously that doesn't have rich literals). Build dependencies and process that again can't be efficiently specified in the native literal forms of the language.

Finally Java has no useful pedigree as a client side or UI language. Thus the J2ME fiasco. The AWT fiasco. The android sluggish UI fiasco.

You can write a modern web app in BCPL, or Java. But for many people the other options are simply more appealing.