Whether or not they want, or will want, to do it at some point, is unknown; the reasons to not do it now are obvious:
1) it's more profitable to keep renting intelligence per token to everyone, preserving the status quo and milking it indefinitely (i.e. while the models aren't yet good enough to reliably single-shot complex software products from half-baked prompts, because once they get there, disruption will happen organically)
2) trying to compete with ~every other software product today is not likely to succeed in the end; a serious attempt would still burn down the software industry, but the major players don't have the capacity to handle it all at once, and doing it gradually will give enough time for regulatory agencies to try and stop it; either way, no one wins