top 10 reasons I dont use rails

So after a very nice dinner catching up with an old friend, I got asked why don't I use rails for my next webapp project. I replied about how I keep meaning to learn rails (and even bought a book to read) but that I'm more comfortable sticking to helma (the javascript-based app server framework I'm using).
But this got me thinking, apart from my inherent laziness, why aren't I using rails?
Well heres my top 10 reasons after a bit more thinking about it:

1. helma is implemented on top of a standard java servlet container (Jetty) so I get to reuse all my existing j2ee knowledge/experience and techniques (eg. mod_jk connector to apache)
   
2. it uses standard java technologies (eg. JDBC) so again same as above
3. it can directly and very easily use any java library and at this point, its arguable java has surpassed even C as the library lingua-franca, especially for things you do for webdev
4. Using Java libraries means if something goes wrong I get a java exception trace which is helpful (since I mainly use oss java libs which come with source) unlike the less helpful: "Segmentation Fault" that you would get with using C libs with rails
5. Another thing about being able to use Java libs is that its really easy to write my own, wrap up/modify existing ones, etc. which I definitely can't do with C libs (my C coding days are a long way behind me)
   
6. I only need learn 1 new language for both the client and server side programming tasks. Its arguable the Ruby is a nicer/better lang then JS but JSs simplicity really appeals to me (warts & all)
7. While they are hardly alike (except for having a common first name) I find javascript syntax at least close enough to javas' to feel quite comfortable and not get a mental 'jarring' that happens every time I try to read ruby code
   
8. JS is also becoming a very popular language and while ruby isn't exactly hard to learn for java programmers, JS is certainly better for me at my current work where the only other tech people are web designers with only JS or AS (actionscript) knowledge
9. performance with helma is excellent, especially with jetty and the rhino JS engine that uses "under the hood" and the memory footprint is excellant too. Now I've only heard here say about rails (rubys) poor performance but thats enough to put me off, especially since with helma I know I can always fall back on using standard java profiling tools and optimising the frameworks underlying code (got know chance to do that with rails ruby interpreter written in C)
10. Even though its not the "out of the box" templating system, I can use Velocity templates with helma in a fairly nice way (and its such a simple integration that I've taken over maintaining it from the original author and have stated adding some small enhancments of my own). As far as I understand, rails goes down the whole nasty "code in pages" road (ala JSP) and that leads to no place I want to be.
    

well they aren't really in any particular order of importance but for me they are pretty compelling reasons to stick with helma and only read a rails book in my (very limited) spare time.
now there are downside compared wit what I already know about rails:

• no scaffolding
  
• no builtin unit testing
• no builtin support for db migrations

but so far none of these are deal breakser for me and in fact I'm slowly working on adding those features to helma myself.
And another one of the down sides to using helma vs rails is the huge community (comprised of a fair few j2ee refugees) that has sprung up around rails. I certainly don't feel the need for that with helma but I think it would be nice not to be off on my own little island - so I'm finally going to set aside a bit of time and write up a short series of helma "intro" articles here - which if they work out ok, might even form the basis of a nice little book: 'server side js: web development with helma" :-)