I study student loans quite a bit and while I agree that there is a bubble it is wholly different than the housing or tech bubbles.
1. About 85% of all student loans are owned by the federal government. There's just over $1tr in loans and only ~150bn are owned by private companies, largely Sallie Mae, Access, Keycorp and a few others. Of those the bulk of the new ones are co-signed (~90%).
2. By and large the irrationality, relative to other assets and within student loans, isn't there for student loans and have already shaken out. Loans like Direct-To-Consumer products offered by First Marblehead have already resulted in the bankruptcy and liquidation of TERI. The marked learned its lesson and stopped offering those.
However...
3. There is no underwriting to majors or ability to repay.
But...
4. Since the federal government owns 85% it is largely seen as a entitlement program and has almost unlimited support within Congress. After all, nobody wants to go on record for being the person who stopped people from seeking higher education. Even if the default rate on student loans approaches 20% (according to DOE we are ~16-17%, but that is revised up every release), its still not a big enough number to drive change. That's "only" $170bn in losses, but doesn't include interest revenue.
I read a lot of research out of DC and there is just no impetus to fix the problem. While the bubble won't take down companies or even the USG, it will be a massive drag on our economy since the loans cannot be discharged and you are creating a debt slave class which cannot hope to repay the loans. This will negatively impact household formation, parent retirement (nobody wants to retire if they have to pay on cosigned loans or have their kids live with them because they can't afford to live on their own)...etc which will be a *massive* drag on GDP cumulatively.
As far as dischargability - there isn't really any support for it right now nor do I see it in the near term. Perhaps in 5+ years, if the Dems take more control and the problem becomes too much to bear.
However, even then, it won't be easy since there will be some pretty large hurdles to getting it discharged.
As far as a bond bubble, I do think there is a small one but it isn't something that cannot be weathered.