It depends on your perspective as to what a single talent is.
computing systems are truly complex beasts and the more you think you know, the more there is to know.
Bigger companies are better at recognising your CSS JS and XHTML talents because their systems are so complex that one person simply cannot do it all, even if they had the time its impossible not just too hard.
Smaller companies, typically deal with smaller systems and so you end up being a “jack of all trades”. This is not limited to computing but true of other professions as well.
At 26 you are not old by any stretch, so take heart in the amount of stuff you’ve got ahead of you in your career, else you’d get bored eventually.
Outside the web world as Brightonmike astutely points out, the “back end” means mainframe computer with its presentation layer being distributed with the help of a complex client and server duality using css and xhtml ..etc on the client, jjms ejbs and mdbs etc.. on the server and then through to MQ and ims and cics regions or similar conduits on the mainframe for true processing grunt.
Each technology has distinct objectives. Cobol is designed for records processing and business is all about records processing when you get down to it. so cobol with a mainframe for virtually limitless computing power is used by large companies and there’s a world within them believe me.
It may also be worth stating that a substantial study done in the USA found that the top 5 reasons for new hire fails, has technical fit as the least reason.
1 coachability – can learn from their peers and bosses
2. emotional intelligence – can withhold their emotions when things don’t go their way
3 motivation – Daniel Pink video – autonomy, mastery, sense of purpose
4 temperament – myer briggs scores show your preference for certain types of behaviours
throughout our lives we all struggle with number 2.