As has been stated, the first example is a classic "dangling modifier." By dangling modifier, I mean that your sentence has an dependent clause (As a skilled programmer ...) that isn't modifying or supporting an independent clause.
So in other words, the meaning of the sentence, "As a skilled computer programmer, this new language is crap," is unclear.
To me, that says,"This new language is crap as a skilled programmer."
The second example fixes the problem by making clear what the clause is modifying, which is clearly you. You are correct in your assessment that the subject of the sentence is unambiguous only in the second sentence. There's no subject at all in your first; or rather, the subject in the first example is "this new language."
At the very least, every sentence must have a bare minimum on one independent clause (i.e. a clause that is by itself a complete sentence). While your sentence does technically contain an independent clause, it's functioning similarly to a dependent one because, logically, the language in and of itself can't possibly do programming, suggesting that the subject was omitted.
This is not a big error in speech among peers, but in formal writing, it would be taboo. I understood it because it's the only logical/possible interpretation. This is an error that I'd avoid in academic/professional writing and is something I would avoid both in speech and in writing in front of a prospective employer. But, in this case, it's more a case of speaking/writing to your audience.
Note that while your example was clear despite not being grammatically correct, there are times when dangling modifiers can make a sentence have multiple meanings.
For example, does "As a skilled programmer, this language is in simple English," mean that the language in question written in simple English? Or does it instead imply that it appears as simple English in the eyes of a skilled programmer?