I am not aganist any frmawork or tool that makes life easier for the developer.
Unfortunately, most of these do the reverse.I have just completed a project that uses OJB for ORM.This was the tool I had recommended from a host of tools evaluated.
Guess what? I found this wanting in many areas, with bugs that the auhors do not think worth fixing
For example if I want to insert records in a batch , ojb.0.9.xx version has no support for it.Likewise if database restarts , I am left with stale connections from the pool.There could be others as well.
This is of course the issue with open source tools.(You can't complain when the stuff is free).My own experience is to use home grown stuff in areas whose execution is critical for the success of the project, or use products that have support from the vendor,else you will end up debugging the vedor's code instead of your own :)
As regards developer comunity not comfortable with bytecode manipulation,this becoes a problem when you have a globally distributed develpoment team that uses the same source from a central repository. versioning binaly files in CVS that are actually source, somehow doesn't make sense
As regards homegrown implemenations, these start at a very simple scale and evelove into full fledged frameworks that support XML mapping, polymorphism, multiple table queries ,complex joins,Object caching and life cycle management.The point is in any well managed project that follows a development methodology( not XP),there is a full set of collateral pertaining to archiecture design and implemenation with profuse documenation will exist. I can vouch for this for all CMM level 3+ or ISO 9001 companies in India.So knowledge transfer is never a problem
Anyway I don't think what Sun dishes out is always holy writ( same about Microsoft as well).So my suggestion about building on our own if time and money permits