1) Tech jobs (especially in software fields) are some of the easiest to do remotely. Creating higher barriers to H1-B visas will only create higher incentives to let those same workers work from their home countries instead of bringing them all the way to the US. The unintended side-effect of course is that this is actually cheaper for the employers, siphons spending outside the US economy and to the extent this is believed to be zero-sum market (it's not), you have to believe that this will depress the job market here.
2) Software is not the only field H1-B jobs are used in. There are whole categories of jobs where $130K salary is absurdly high even for top candidates (without any visa restrictions). Case in point, academic researchers and scientists.